Siam Commercial Bank Issuer Summary

Report date: 2026-05-13
Issuer: The Siam Commercial Bank Public Company Limited
Sector: Thai banking
Primary credit focus: SCB bank-standalone issuer credit, senior unsecured bonds, and the separation of SCBX group-structure considerations from government support expectations

1. Business Snapshot and Recent Developments

Siam Commercial Bank is a major universal bank in Thailand. Established in 1906 by royal charter, it was Thailand’s first bank and now offers a broad range of products and services, including deposits, mortgages, personal loans, auto-related credit, corporate lending, SME finance, cash management, trade finance, capital markets, investment banking, and wealth products. At end-2025, SCB consolidated total assets were Baht 3.50 trillion, loans were Baht 2.25 trillion, and deposits were Baht 2.59 trillion. In the Thai commercial banking sector in the same year, SCB had market shares of 15.4% in total assets, 13.1% in loans, 15.4% in deposits, and 18.6% in net profit.

In this report, “SCB consolidated” refers to the consolidation of the SCB banking entity, “SCB bank-only” refers to bank-only disclosures such as C.B. 1.1, and “SCBX consolidated” refers to the consolidated group of the holding company SCB X Public Company Limited. For the analysis of SCB’s senior bonds, it is important not to conflate these three bases of reporting.

The first distinction to make for this issuer is between SCB bank-only and the SCB X Public Company Limited (“SCBX”) group. As of 30 December 2025, SCBX held 99.56% of SCB’s issued shares, and SCB is the core banking subsidiary of the SCBX group. SCBX is a holding company that houses SCB, CardX, AutoX, InnovestX, SCB 10X, DataX, TechX, and other digital and financial-services companies, and in 2026 it also launched a virtual bank called BankX. For investors in SCB’s senior unsecured bonds, the direct repayment resources to analyse first are the assets, deposits and market funding, regulatory capital, liquidity, earnings, and provisions of the SCB banking entity.

In 2025, SCB maintained a strong capital and deposit base, while earnings came under pressure from lower interest rates. SCB consolidated net profit was Baht 45.8 billion in 2025, down 6.9% from Baht 49.2 billion in 2024. The main driver was a decline in net interest income, which fell 10.1% from Baht 104.6 billion to Baht 94.0 billion. NIM declined to 2.8% in 2025 from 3.3% in 2024. This reflected policy-rate cuts by the Bank of Thailand, a decline in loan balances, and selective underwriting focused on risk-adjusted returns. However, non-interest income increased 13.7% to Baht 44.6 billion, and operating expenses fell 3.4% to Baht 53.5 billion, keeping the cost-to-income ratio contained at 38.6%. Credit cost was Baht 28.0 billion, or 124bp of loans, including a Baht 4.5 billion management overlay for future risks.

The main data points available for 2026 are not detailed bank-only financial statements, but primarily SCB bank-only monthly balance-sheet data and SCBX’s consolidated first-quarter release. In SCB’s bank-only C.B. 1.1 at end-March 2026, total assets were Baht 3.584 trillion, deposits were Baht 2.653 trillion, loans and accrued interest receivables net were Baht 2.194 trillion, the total capital ratio was 18.42%, and the NPL ratio was 3.07%. In the same C.B. 1.1 at end-December 2025, total assets were Baht 3.503 trillion, deposits were Baht 2.586 trillion, loans and accrued interest receivables net were Baht 2.138 trillion, the total capital ratio was 18.95%, and the NPL ratio was 3.12%. Over the three-month period, the balance sheet expanded and the NPL ratio declined slightly. However, SCB bank-only P/L, NIM, credit cost, and Stage 2 ratio for 1Q 2026 have not been obtained for this report.

On an SCBX consolidated basis, 1Q 2026 net profit was Baht 10.195 billion, down 18.5% year on year. The company attributed this mainly to NIM compression following four policy-rate cuts in 2025 and one in February 2026, as well as lower investment gains. At the same time, fees and other income were Baht 11.962 billion, up 17.7% year on year, the NPL ratio was 3.23%, the coverage ratio was 162.3%, and the capital adequacy ratio was 18.0%. These figures are for SCBX consolidated and should not be directly substituted for the rating or bond assessment of SCB bank-only.

On management, SCBX announced on 4 March 2026 the appointment of Sarut Ruttanaporn as CEO of SCB. The appointment became effective on 1 May 2026. This change does not immediately alter capital or liquidity, but it needs to be monitored because it is relevant to how SCB combines traditional banking, wealth management, digital lending, and intra-group coordination in its business strategy and risk appetite from 2026 onward.

The key point in SCB’s credit analysis is not only its strong deposits and capital, but also the lagged risk that Thailand’s macro environment poses to banks. The Bank of Thailand stated that, for the banking sector in 2025 and 4Q 2025, loans declined 1.1% year on year, with continued contraction in SME and consumer lending. At end-2025, the sector NPL ratio was 2.84%, the Stage 2 ratio was 7.07%, the BIS ratio was 20.9%, LCR was 215.1%, and NPL coverage was 183.2%. SCB’s end-2025 NPL ratio of 3.14% was somewhat above the sector level, while its coverage ratio of 156.5% was below the sector average. This does not mean that SCB is a weak bank, but it does indicate the need to examine carefully the quality of household, SME, SSME, and retail credit even among “major Thai banks”.

The bond context confirmed for SCB at this stage is the USD 500mn 4.40% senior unsecured notes due February 2029 disclosed in the 2025 annual report. The offering circular, governing law, cross-default, change of control, bail-in or loss-absorption provisions, and security or guarantee details for individual bonds have not been confirmed in this report. Investment conclusions based on individual bond terms therefore remain pending.

2. Industry Position and Franchise Strength

Thailand’s banking system is structured around major domestic banks that provide deposits, corporate lending, mortgages, payments, capital markets, and wealth management. Within this system, SCB is not a mid-tier bank but one of the major domestic banks. The 2025 annual report defines the Thai commercial banking sector as 17 domestically registered banks and reports SCB’s total assets of Baht 3.504 trillion, loans of Baht 2.250 trillion, deposits of Baht 2.586 trillion, and net profit of Baht 45.9 billion. Market shares in the mid-15% range for total assets and deposits, the 13% range for loans, and the 18% range for net profit show that SCB’s franchise is not a niche business, but an important part of financial intermediation in Thailand.

The first strength of this franchise is its deposit base. At end-2025, SCB consolidated deposits were Baht 2.586 trillion, exceeding loans of Baht 2.250 trillion, with a loan-to-deposit ratio of 87.0%. This was down from 91.5% at end-2024 and does not suggest a structure in which the bank is chasing deposit funding to support rapid loan growth. In bank credit, deposit stability reduces reliance on market funding and mitigates refinancing risk under stress. In SCB’s case, deposits also increased to Baht 2.653 trillion in the bank-only C.B. 1.1 at end-March 2026, suggesting that balance-sheet expansion was supported by deposit growth.

The second strength is SCB’s broad customer interface across corporate, SME, retail, wealth, and digital channels. SCB’s business is divided into Corporate & International, SME & SSME, Retail & Wealth, and other revenues. In the 2025 revenue mix, Retail & Wealth accounted for 44%, Corporate & International for 23%, SME & SSME for 19%, and Others for 14%. Retail & Wealth is the largest revenue contributor and builds customer relationships through deposits, mortgages, personal finance, investment and insurance products, and wealth services. Corporate & International supports large corporates, capital markets, trade finance, and cash management. SME & SSME sits closer to the base of the Thai economy, but is sensitive to the economy, cash flow, and collateral values, and is also more likely to become a source of credit costs.

The third strength is the penetration of digital channels. At end-2025, SCB EASY App users totalled 15.5 million, with a monthly active ratio disclosed at 80.9%. Branches and express service outlets declined from 684 in 2024 to 625 in 2025. This is positive for cost efficiency and the digitalisation of customer interfaces. However, as digital channels expand credit origination and cross-selling, fraud, cyber risk, model risk, customer protection, and data management also become more important.

At the same time, franchise constraints are also clear. In 2025, the Thai economy was affected by slowing private consumption, household debt, subdued tourism growth, weakness in manufacturing, and geopolitical and tariff uncertainty. Precisely because SCB is a major bank, it cannot escape this domestic credit cycle. A high market share is a strength in terms of deposits and customer base, but it also means that some exposure to weaker domestic borrowers is unavoidable.

SCB’s industry position is relatively strong in terms of profitability. Its 2025 profit share of 18.6% exceeded its loan share of 13.1%. This indicates that SCB is not earning solely from loan volume, but is generating relatively strong profit through a revenue mix that includes wealth management, fees, investment gains, and cost control. However, SCB’s net profit declined year on year in 2025, and whether it can maintain its profit share in a lower-rate environment remains to be tested.

In one sentence, SCB’s franchise can be described as “a major Thai bank with deposits, customer access, a digital base, and wealth revenues in the domestic market”. However, these strengths do not eliminate Thai household and SME credit risk, NIM pressure, or operational risk in digital finance. For credit investors, the task is to recognise the strength of the banking franchise while continuing to monitor how much lagged deterioration in domestic small-ticket credit erodes earnings and capital.

3. Segment Assessment

When assessing SCB’s segments, it is necessary to separate the revenue mix from the risk mix. Retail & Wealth is the largest contributor by revenue, followed by corporate and SME. Credit risk, however, does not necessarily emerge in line with revenue shares. Retail & Wealth includes deposits, investment products, mortgages, and personal loans; it supports the franchise but is exposed to household debt, unemployment, and income stagnation. SME & SSME is close to Thailand’s real economy and is more likely to generate delinquencies, restructured loans, and NPLs in a downturn. Corporate & International has deep relationships with large clients and generates capital-markets and cash-management revenues, but large-name and sector concentrations need to be assessed separately.

The customer-segment revenue mix from 2023 to 2025 is as follows. The figures are composition ratios based on disclosures in SCB’s annual report and are not segment profit, RWA, NPL, or credit-cost figures.

Retail & Wealth is the most important division supporting SCB’s brand and customer access. Mortgages, personal finance, deposits, investment products, insurance, and wealth services provide recurring customer relationships and fee opportunities. In 2025, wealth-management-related fees supported non-interest income, making the segment important in a period of NIM compression.

However, it is insufficient to view Retail & Wealth simply as stable revenue. Thailand has a high level of household debt, and SCB’s small-ticket lending is sensitive to income stagnation and higher living costs. Within the SCBX group, there are also non-bank and digital-lending companies such as CardX, AutoX, and MONIX. Although these are separate legal entities from SCB bank-only, they are useful indicators of the group’s overall credit-risk culture and risk appetite.

Corporate & International is the corporate base that supports bank credit. Large-corporate lending, cash management, trade finance, financial markets, investment banking, and capital-markets services tend also to bring fee income and deposits. However, corporate exposure is affected by large-name concentration, sector concentration, external demand, tourism, property, and supply chains. For SCB’s corporate division to support earnings, it needs risk-adjusted returns, fees, and relationship depth, not merely loan volume.

SME & SSME is the segment that should be treated most cautiously in SCB’s credit analysis. The annual report explains that the decline in loans in 2025 was driven mainly by reductions in auto loans and the SSME portfolio. This has both a positive aspect, in that the bank is reducing higher-credit-risk exposures, and a constraint, in that SME/SSME borrowing demand or creditworthiness is weak and loan-growth headroom is limited.

Others includes Group Treasury, financial-market transactions, investments, subsidiaries, and associates. Investment gains can supplement earnings, but they should not be placed at the centre of bank credit analysis. What credit investors should assess is whether sufficient core earnings remain from net interest income, fees, cost management, and credit costs even without investment gains.

As a segment assessment, Retail & Wealth is a strength in terms of deposits, customer interface, and non-interest income, while Corporate & International supports the corporate base and fee income. SME & SSME is important over the long term as an interface with the Thai economy, but in the 2025-2026 credit cycle it should be treated as the most vulnerable area. Others supplements earnings through investment and market-related revenue, but it is volatile and is not a substitute for core earning power.

4. Financial Profile and Analysis

SCB’s financial profile shows adequate profit, capital, and deposits for a bank, but the earnings direction from 2025 into 2026 is not easy. Net interest income has declined due to lower policy rates and selective lending, while the NPL ratio has improved but remains above the sector average. Capital ratios and provisions are adequate, but if credit costs persist, the bank will be buying time through capital buffers rather than earnings growth.

The five-year trend in key financial indicators is as follows. The figures are on the SCB annual-report consolidated basis, and capital ratios are on a Basel III basis.

The largest earnings change is the decline in NIM and net interest income. Net interest income was Baht 94.0 billion in 2025, down 10.1% year on year, and NIM fell to 2.8%. SCBX’s 1Q 2026 release also identifies NIM compression from policy-rate cuts as the main reason for the decline in net interest income. Therefore, in assessing SCB’s core earnings capacity, the higher NIM levels of 2022-2024 should not be treated as the normal run rate; the relevant question is whether the bank can absorb credit costs at the lower spread levels prevailing from 2025 onward.

Non-interest income recovered to Baht 44.6 billion in 2025. The company cited investment gains, wealth-management fees, loan-related fees, and transaction-banking fees as positive drivers. However, on an SCBX consolidated basis in 1Q 2026, investment and trading income declined 66.5% year on year. When evaluating the strength of non-interest income, recurring revenues such as wealth management and payments need to be separated from investment-portfolio gains.

Costs were relatively well controlled. Operating expenses declined 3.4% year on year to Baht 53.5 billion in 2025, and the cost-to-income ratio was 38.6%. Cost efficiency is an important defence for a bank whose revenues decline in a lower-rate environment. However, as digital investment, AI, cybersecurity, BankX, and coordination with new intra-group businesses continue, it will be difficult to protect profits through cost reduction alone indefinitely.

Asset quality has improved, but not to a point where strong optimism is warranted. SCB consolidated NPLs were Baht 88.6 billion at end-2025, down 2.3% from Baht 90.7 billion at end-2024, and the NPL ratio improved from 3.28% to 3.14%. At the same time, the Thai commercial banking system NPL ratio was 2.84% at end-2025, meaning SCB was above the sector average. In addition, the NPL ratio is a lagging indicator. It is difficult to conclude that credit risk has sufficiently stabilised without also analysing Stage 2 loans, restructured loans, delinquencies, and renewed deterioration after rescheduling.

Provisions are adequate but not exceptionally thick relative to the sector. SCB’s coverage ratio was 156.5% at end-2025, up from 152.3% at end-2024. Expected credit loss in 2025 was Baht 28.0 billion, or 124bp of loans, and included a Baht 4.5 billion management overlay. By contrast, the BOT’s end-2025 sector coverage ratio was 183.2%, so SCB’s coverage was below the sector average. Differences in loan mix and collateral mean that a simple comparison is not conclusive, but it is not possible to say that SCB’s provisions are “excessively thick”.

Capital is a clear strength. At end-2025, bank-only total capital was Baht 409.7 billion, RWA were Baht 2.162 trillion, the total capital ratio was 19.0%, and the CET1/Tier 1 ratio was 17.9%. In the C.B. 1.1 at end-March 2026, regulatory capital was Baht 414.8 billion and the total capital ratio was 18.42%. The ratio declined from end-2025, but the absolute amount increased. In the next update, the formal Pillar III disclosure should be used to confirm the breakdown of CET1, Tier 1, RWA, credit risk, market risk, and operational risk.

The main changes in SCB bank-only C.B. 1.1 from end-2025 to end-March 2026 are as follows. This is not an audited annual financial statement, but a monthly summary balance sheet.

The point to note in this table is that short-term improvement at end-March 2026 should not be overemphasised. The NPL ratio declined to 3.07%, but Stage 2 and credit-cost details have not been confirmed. The decline in shareholders’ equity from end-December to end-March also requires confirmation of the effects of dividends, interim profit, other comprehensive income, and capital actions. In bank credit, new NPL formation, Stage 2, restructured loans, credit cost, and provisioning direction matter more than a single-quarter NPL ratio.

Overall, SCB’s financials have sufficient resilience for an investment-grade bank, but the earnings environment from 2025 onward is not easy. NIM pressure has reduced PPOP headroom, the NPL ratio remains above the sector average despite improvement, and the coverage ratio is below the sector average despite improvement. Capital and deposits are strong, but to make a stronger claim of credit improvement, it is necessary to confirm another layer of bank-only 2026 earnings, Stage 2, retail and SME asset quality, and Pillar III capital and liquidity details.

5. Structural Considerations for Bondholders

The first structural issue for SCB bondholders is that the issuer is not the SCBX holding company but the Thai banking entity, The Siam Commercial Bank Public Company Limited. After the 2022 restructuring, SCBX took responsibility for growth strategy, capital allocation, and digital-finance businesses as the parent company, but bank creditors have a legal claim against SCB bank. Therefore, before considering SCBX’s consolidated growth story, it is necessary to analyse SCB bank-only assets, deposits, capital, liquidity, and regulatory position.

SCB bank’s senior unsecured bonds are not instruments that structurally depend on subsidiary dividends in the way a holding-company bond would. At the same time, within the banking entity they sit alongside deposits, interbank obligations, derivatives, secured transactions, and supervisory resolution treatment. Therefore, the ranking, subordination, loss absorption, governing law, and covenants of individual bonds cannot be concluded without reviewing the offering circular. The foreign-currency bond confirmed in the 2025 annual report is the USD 500mn 4.40% senior unsecured notes due February 2029, but this report has not reviewed the offering documents. Change of control, cross-default, negative pledge, tax gross-up, early redemption, events of default, and the relationship with Thai bank resolution therefore remain unconfirmed.

The relationship with the parent company SCBX has two credit dimensions. SCB is the core bank of the SCBX group and the centre of the group’s assets, earnings, and deposit base, so the parent’s incentive to use capital or liquidity in a way that damages bank credit should be limited. On the other hand, CardX, AutoX, BankX, digital lending, and AI and data businesses carry retail credit risk, cyber risk, conduct risk, model risk, and investment burden. The degree to which these risks may spill over to bank-only credit is not sufficiently visible from public information, so SCBX’s new businesses should not be treated as an unqualified positive for bank bonds.

Government support expectations should also be treated as a supplementary factor. SCB’s annual report states that the bank is treated as a Domestic Systemically Important Bank (D-SIB) and is subject to a D-SIB buffer of 1.00%. Fitch’s Government Support Rating, the gap between Moody’s BCA and deposit ratings, and the gap between S&P’s SACP and issuer credit rating also indicate that support and systemic importance are reflected in the ratings in addition to standalone credit. However, this is not an explicit guarantee. SCB’s senior unsecured bonds should not be described as “guaranteed by the Thai government”; the analysis should first assess how much resilience the bank has from its own capital, liquidity, earnings, and asset quality.

6. Capital Structure, Liquidity and Funding

SCB’s capital and funding are currently its strongest credit pillars. At end-2025, the bank-only total capital ratio was 19.0% and the CET1/Tier 1 ratio was 17.9%, providing ample headroom even after considering the 1.00% D-SIB buffer stated in the annual report. In the C.B. 1.1 at end-March 2026, the total capital ratio was 18.42%. The ratio declined slightly, but the amount of regulatory capital increased to Baht 414.8 billion. The fact that most total capital is Tier 1 also supports the quality of loss-absorbing capacity.

Funding is deposit-led. At end-2025, deposits were Baht 2.586 trillion, loans were Baht 2.250 trillion, and the loan-to-deposit ratio was 87.0%. In the bank-only C.B. 1.1 at end-March 2026, deposits were Baht 2.653 trillion and loans and accrued interest receivables net were Baht 2.194 trillion, so deposits continued to exceed loans by a substantial margin. Debt issued and borrowings were Baht 23.67 billion at end-December 2025 and Baht 32.76 billion at end-March 2026, small relative to deposits. SCB is not an issuer that depends heavily on market debt.

However, this report has not sufficiently confirmed the detailed composition of deposits, top-depositor concentration, foreign-currency deposit ratio, maturity distribution, or SCB-specific LCR/NSFR. According to Bank of Thailand materials, the commercial banking system LCR was 215.1%, the BIS ratio was 20.9%, and NPL coverage was 183.2% at end-2025, but sector averages cannot be used as SCB-specific figures. In liquidity analysis, the deposit base, low loan-to-deposit ratio, and small amount of market debt suggest contained funding-liquidity risk, while capital should be treated separately as an element supporting loss absorption.

For market debt, the USD 500mn 4.40% 2029 senior unsecured notes have been confirmed. Foreign-currency bond investors need to review the ability of a bank supported by Baht deposits to repay foreign-currency obligations, foreign-currency liquidity, FX hedging, regulatory foreign-currency management, and sovereign and country risk. Because this report has not confirmed currency-level ALM, foreign-currency bonds are assessed mainly from the issuer-credit perspective, with offering documents and foreign-currency liquidity to be checked before individual investment decisions.

In conclusion, SCB is supported by deposit-led funding, a high total capital ratio, a high Tier 1 ratio, and a low loan-to-deposit ratio, and is distant from short-term funding-driven credit stress. The main risk path is not deposit outflow or dependence on market debt, but a prolonged period of lower NIM and credit costs gradually eroding PPOP and internal capital generation.

7. Rating Agency View

The rating agencies assess SCB as an investment-grade bank while distinguishing standalone credit from government support and systemic importance. SCB’s official Credit Ratings page, using the latest table confirmed as of 13 May 2026, shows Moody’s outlook Stable as of 22 April 2026, bank deposits of Baa1/P-2, senior unsecured MTN of Baa1, and BCA of baa2. S&P shows an issuer credit rating of BBB/Stable/A-2, senior unsecured of BBB, and SACP of bb+ as of 20 December 2024. Fitch shows a foreign-currency long-term IDR of BBB, outlook Stable, national long-term rating of AA+(tha), viability rating of bbb, and government support rating of bbb as of 24 June 2025.

Looking separately at Moody’s BCA, S&P’s SACP, and Fitch’s VR/GSR shows that SCB’s ratings are a composite assessment incorporating not only standalone credit but also systemic importance and government support expectations. This is credit positive, but it is not an explicit guarantee. Investors should use the investment-grade ratings around BBB/Baa1 as signals of market access and systemic importance, while separately monitoring NIM pressure, NPL/Stage 2, coverage, and the direction of capital ratios.

8. Credit Positioning

SCB’s credit positioning can be summarised as “a top-tier domestic Thai, deposit-led bank whose investment-grade ratings partly reflect systemic importance and support expectations in addition to standalone credit”. It has the scale, deposits, capital, and profit share of a major bank, while also facing lower interest rates from 2025 onward, household and SME vulnerability, a relatively high NPL ratio, and the complexity of the SCBX group strategy. SCB is not a “strong bank that does not need to be monitored”; it is a bank with investment-grade resilience that still retains sensitivity to the domestic small-ticket credit cycle.

Compared with other major domestic Thai banks, SCB is in the top tier by total assets, loans, and deposits, and has a significant profit presence, with a 2025 net profit share of 18.6% versus a loan share of 13.1%. However, net profit declined in 2025, and the sustainability of investment gains and cost reductions needs to be confirmed. Compared with similarly rated Asian banks, its strengths are its domestic franchise and systemic importance, while its constraints are concentration in the Thai sovereign, household debt, policy rates, tourism and exports, and domestic regulation.

Within the SCBX group, SCB is less a mere bank subsidiary than the group’s credit foundation. SCBX’s 2025 full-year net profit was Baht 47.488 billion, while SCB banking consolidated net profit was Baht 45.8 billion, making clear that the banking business is central to group earnings. Growth in SCBX’s digital-finance and consumer-finance businesses may supplement credit over time, but it is necessary to confirm that these initiatives are executed without damaging the bank’s capital, deposits, or regulated credit profile.

This report does not make relative-value judgments based on market spreads or individual bond prices. Bloomberg, live pricing, OAS, Z spread, and CDS are not available in the normal working environment for this project. Fundamentally, SCB’s senior unsecured bonds are instruments taking investment-grade Thai major-bank risk, and the main sources of risk premium are the Thai sovereign, the domestic banking sector, household and SME risks, NIM compression, and the currency, jurisdiction, and terms of foreign-currency bonds.

9. Key Credit Strengths and Constraints

SCB’s credit profile is a combination of strong supports from deposits, capital, and systemic importance, and constraints from lower NIM, domestic small-ticket credit risk, and group-strategy complexity. The issuer credit profile is sufficiently investment grade, but describing it simply as a “stable major bank” would blur the risks that actually need to be monitored.

The main credit strengths are as follows.

The core strengths are deposits and capital. SCB funds its loans comfortably with deposits and has strong CET1/Tier 1 capital. The fact that it maintained net profit of Baht 45.8 billion and ROE of 10.4% despite NIM compression in 2025 indicates that the earnings base remains adequate. Its systemic importance as a D-SIB, investment-grade ratings, and core status within the SCBX group also mitigate short-term market-access and credit-confidence concerns.

The main constraints are as follows.

The largest constraints are NIM pressure and asset quality. In 2025, credit cost increased even as net interest income fell substantially. Non-interest income and cost reductions absorbed this, but there is no assurance that this can be repeated every year. If, in 2026, the impact of lower rates continues, loan growth remains weak, and retail and SME credit costs rise again, PPOP and internal capital generation will be pressured.

The SCBX group strategy cuts across both strengths and constraints. Digital channels, wealth management, virtual banking, consumer finance, and AI/data use may support SCB’s long-term competitiveness. At the same time, when a banking group pursues growth by expanding small-ticket or digital lending, model risk, underwriting standards, conduct, cyber risk, data management, and intra-group capital allocation must be monitored. For credit investors, the key point is not the growth strategy itself, but whether it is executed without damaging the bank’s capital, liquidity, and asset quality.

10. Downside Scenarios and Monitoring Triggers

SCB’s downside lies less in acute deposit outflow and more in a scenario where the domestic credit cycle and NIM decline proceed at the same time, gradually eroding earnings and capital buffers. Given its deposit base and capital ratios, SCB is not an issuer to analyse primarily through short-term insolvency risk. However, even for an investment-grade bank, a combination of lower earnings, higher credit costs, and a weaker rating outlook can affect bond spreads and market access.

There are five main deterioration paths. First is asset-quality deterioration in retail, SME, and SSME. The NPL ratio on a C.B. 1.1 basis improved slightly from 3.12% at end-December 2025 to 3.07% at end-March 2026, but NPLs are a lagging indicator, and Stage 2 loans, restructured loans, delinquencies, and renewed deterioration after payment relief need to be reviewed. Second is a prolonged period of NIM decline and loan contraction. NIM declined to 2.8% in 2025, and on an SCBX consolidated basis net interest income fell 13.7% year on year in 1Q 2026. Third is the possibility that SCBX’s digital and consumer-finance strategy spills over to bank credit through credit costs, regulation, cyber risk, conduct risk, and model risk. Fourth is a decline in capital ratios due to RWA growth, credit losses, dividends, or intra-group capital needs. Fifth is a weaker view of the Thai sovereign, the banking system, or government support expectations.

The main monitoring items are as follows.

In practice, these indicators should be assessed in combination rather than in isolation. Even if the NPL ratio declines, an increase in Stage 2 would warrant caution. Even if NIM declines, the credit impact can be contained if PPOP is maintained through fees and cost management. The credit view on SCB depends on how far the strength of deposits and capital can absorb lower earnings and asset-quality constraints.

11. Credit View and Monitoring Focus

At present, SCB’s senior issuer credit is at a level that can be adequately maintained for an investment-grade bank. The direction of credit quality is broadly stable, supported by a strong deposit base, high CET1/Tier 1 ratio, and systemic importance as a D-SIB confirmed in the annual report. The probability of rapid credit deterioration is not high, but given the decline in NIM and net interest income from 2025 onward and Thai household and SME credit risk, it is also not possible to say that SCB has entered a phase of strong credit improvement.

Credit quality is supported by SCB’s top-tier domestic banking franchise, deposit-led funding, high regulatory capital, investment-grade ratings, and core status within the SCBX group. The end-2025 total capital ratio of 19.0%, CET1/Tier 1 ratio of 17.9%, loan-to-deposit ratio of 87.0%, and end-March 2026 bank-only total capital ratio of 18.42% indicate that the bank is distant from short-term funding stress or capital shortage.

The largest constraints are the direction of earnings and asset quality. Net interest income declined 10.1% in 2025 and NIM fell to 2.8%. The NPL ratio improved to 3.14%, but remained above the 2.84% level for the Thai commercial banking system, and the coverage ratio of 156.5% was also below the sector average of 183.2%. SCB is a bank that absorbs NIM pressure and domestic small-ticket credit risk through capital and deposits.

The SCBX group strategy should be treated as a secondary line of analysis in the credit view. CardX, AutoX, BankX, digital finance, and AI use may contribute to long-term earnings diversification, but they are not direct repayment resources for bank bondholders. They should be monitored as indicators of whether group risk appetite, capital allocation, conduct, cyber risk, and model risk might spill over to SCB bank-only.

The conditions for an improved credit view would be that SCB’s 2026 bank-only earnings maintain PPOP even after NIM compression, NPL and Stage 2 remain stable at the same time, credit costs in retail, SME, and SSME do not rise again, and the CET1 capital amount and total capital ratio remain high. Conversely, if revenue decline, higher delinquencies, lower coverage, consumer-finance or digital-lending losses, and a decline in capital ratios occur at the same time, the view would need to be adjusted in a weaker direction even within investment grade. Because live spreads have not been confirmed, this report does not make a relative-value judgment, but fundamentally the senior credit has adequate resilience. However, SCB bank-only Stage 2, individual LCR/NSFR, currency-level ALM, and foreign-currency liquidity have not been confirmed and are priority items for the next update.

12. Short Summary & Conclusion

Siam Commercial Bank is a major universal bank in Thailand with a large domestic deposit and loan base, and is the core banking subsidiary of the SCBX group. A high CET1/Tier 1 ratio, deposit-led funding, and systemic importance as a D-SIB confirmed in the annual report support senior issuer credit, while NIM pressure from 2025 onward, retail and SME credit risk, and the SCBX group’s digital and consumer-finance strategy require monitoring. The senior credit has sufficient resilience for investment grade, but government support expectations should not be confused with an explicit guarantee. This is an issuer where bank-only asset quality, PPOP, capital, and liquidity should continue to be monitored.

13. Sources

Company and primary sources

• The Siam Commercial Bank Public Company Limited, Financial Information page, accessed 2026-05-13. Used to confirm the location of the March 2026 C.B. 1.1, December 2025 C.B. 1.1, ratings table, and annual report.
  https://www.scb.co.th/en/shareholders/financial-information/
• The Siam Commercial Bank Public Company Limited, Annual Report 2025. Used to confirm the five-year key statistics, MD&A, segment revenue mix, shareholder structure, capital, D-SIB buffer, ratings, and the 2029 senior unsecured bond.
  https://www.scb.co.th/content/media/investor-relations/documents/annual-reports/en/annual-report-eng-2025.pdf
• The Siam Commercial Bank Public Company Limited, Summary Statement of Assets and Liabilities (C.B. 1.1) as of March 31, 2026. Used to confirm bank-only total assets, deposits, net loans, NPLs, regulatory capital, and total capital ratio at end-March 2026.
  https://www.scb.co.th/getmedia/96cd3369-94b5-4c54-8b15-9461c71bf0e0/cb11-mar26-eng-scb-bank.pdf
• The Siam Commercial Bank Public Company Limited, Summary Statement of Assets and Liabilities (C.B. 1.1) as of December 31, 2025. Used to confirm bank-only total assets, deposits, net loans, NPLs, regulatory capital, and total capital ratio at end-December 2025.
  https://www.scb.co.th/getmedia/3ab9a750-435a-48c0-a8f8-46a67089eabe/cb11-dec25-eng-scb-bank.pdf
• The Siam Commercial Bank Public Company Limited, About SCB, accessed 2026-05-13. Used to confirm company history and business scope as a universal bank.
  https://www.scb.co.th/en/about-us.html
• SCB X Public Company Limited, SCBX reports first-quarter 2026 net profit of Baht 10,195 million, April 21, 2026. Used to confirm SCBX consolidated 1Q 2026 earnings, NIM compression, NPLs, coverage, capital, and BankX-related discussion.
  https://www.scbx.com/en/news/q1-2026-net-profit/
• SCB X Public Company Limited, SCBX reports 2025 net profit of Baht 47,488 million, January 21, 2026. Used to confirm SCBX consolidated full-year 2025 earnings, expenses, NPLs, coverage, capital, and virtual-bank strategy.
  https://www.scb.co.th/en/about-us/news/jan-2026/scbx-announced-net-profit-4q25
• SCB X Public Company Limited, SCBX Group appoints Sarut Ruttanaporn as new CEO of Siam Commercial Bank effective 1 May 2026, March 4, 2026. Used to confirm the management change.
  https://investor.scbx.com/en/newsroom/press-releases/187779/scbx-group-appoints-sarut-ruttanaporn-as-new-ceo-of-siam-commercial-bank-effective-1-may-2026
• Bank of Thailand, Banking Sector Quarterly Brief Q4 2025 and 2025, February 17, 2026. Used to confirm Thai banking-sector loans, NPLs, Stage 2, capital, LCR, coverage, and SME and household risks.
  https://www.bot.or.th/content/dam/bot/documents/en/news-and-media/news/2026/news-20260217.pdf

Rating and supplementary sources

• SCB official Credit Ratings table, accessed 2026-05-13. Used to confirm Moody's ratings dated 2026-04-22, S&P ratings dated 2024-12-20, and Fitch ratings dated 2025-06-24.
  https://www.scb.co.th/en/shareholders/financial-information/
• Fitch Ratings mirrored release, Fitch affirms SCBX and Siam Commercial Bank at BBB and AA+(tha), Outlook Stable, June 25, 2025. Used as supplementary confirmation of Fitch’s approach to SCB/SCBX group treatment, VR, GSR, and IDR.
  https://www.ryt9.com/en/prg/12723844

Internal working materials referenced

• Internal writing plan and structured metrics file were used for drafting discipline and consistency. They are not public source documents.

Unverified / Pending items