Guide to Investing in T-bills Through CPFIS

Singapore T-bills are short-term government debt instruments that allow investors to lend to the Monetary Authority of Singapore (MAS) for six months or one year. Through the CPF Investment Scheme (CPFIS), ordinary account (OA) balances can be used to buy these zero-coupon securities at auction. In the 2026 May 6-month T-bill auction, the cut-off yield hit 3.85%, delivering a 135-basis-point premium over the CPF OA floor rate of 2.50%. That spread translates into tangible dollars for investors who are willing to navigate the auction process and hold to maturity.

What Are Singapore T-bills and How Do They Fit into CPFIS?

T-bills are issued at a discount to face value and pay no periodic coupon. Their return is simply the difference between the purchase price and the S$100 par they redeem at maturity. For CPF investors, only non-competitive bids are permitted under CPFIS—you accept the cut-off yield determined at auction rather than setting your own price. The security is then held in your CPF Investment Account with an agent bank until maturity, at which point the principal plus implied interest automatically flows back into your OA. Because T-bills are direct obligations of the Singapore government, they carry the same AAA credit profile as your CPF savings themselves.

Step-by-Step: Using CPF OA Funds to Bid at a T-bill Auction

Start by opening a CPF Investment Account with DBS/POSB, OCBC, or UOB if you don’t already hold one. OA investible savings are calculated as your total OA balance minus S$20,000—only the excess is available. The 6-month T-bill auction calendar is published by MAS; typical announcement is three business days before the auction. You must submit your non-competitive application through your agent bank’s online portal or branch by noon on auction day. For the 15 May 2026 auction, that meant logging in before 12 p.m. to indicate a face-value amount (multiples of S$1,000). No cash moves until the issue date, usually three business days later, when your OA is debited. The cut-off yield from that auction, 3.85%, is applied uniformly to all non-competitive bids.

Yield Calculation: Comparing T-bill Returns Against CPF OA Interest

A 6-month T-bill with a cut-off yield of 3.85% on a S$10,000 face value costs approximately S$9,811.50 (price = 100 ÷ [1 + (0.0385 × 182/365)]). At maturity you receive S$10,000, producing a dollar gain of S$188.50. Annualised, that’s exactly the cut-off yield. Meanwhile, leaving the same S$9,811.50 in your OA for six months would earn about S$122.64 in CPF interest (2.50% p.a., half-year prorated). The surplus is S$65.86. On a S$50,000 face investment, the half-year gross gain is S$942.50 versus S$613.20 of forgone OA interest, a net lift of S$329.30. Those extra dollars compound when you redeploy the proceeds into subsequent T-bills or higher-yielding CPFIS instruments.

CPFIS Agent Banks and Fees: What You’ll Pay

Agent banks levy a quarterly service fee of S$2 per counter (capped at S$5 per quarter) for holding SGS securities in your CPF Investment Account. A single T-bill position therefore costs S$8 annually. A one-time application fee also applies: DBS charges S$2.50, OCBC S$2.00, and UOB S$2.00. On a S$10,000 face T-bill bought for S$9,811.50, total six-month costs of about S$6.00 represent a trivial 0.061% drag on invested capital. Larger denominations shrink the fee impact—on a S$100,000 position, the same fixed fees fade to 0.0061%. Run the numbers before you invest: if the cut-off yield minus 2.50% OA rate yields a spread below about 0.10%, fees could consume the benefit.

Risk and Opportunity Cost: When the Spread Doesn’t Pay

The most immediate risk is a narrowing or inversion of the yield spread. In early 2026, 6-month cut-off yields ranged from 3.83% (April) to 3.90% (January), always well above the OA floor. But historical data shows periods—such as 2020—when T-bill yields dipped to 0.17%, making CPF OA the better option. Liquidity is another constraint: under CPFIS, you cannot sell a T-bill before maturity. The funds remain locked until the issue-date anniversary, which could be problematic if you need OA money for a housing loan installment. The CPF interest calculation also matters; your OA balance loses one month’s interest on the amount withdrawn, and only earns again from the day funds return. For a 6-month tenure, the net effect typically shaves 0.05%–0.10% off the annualised spread, so a cut-off yield of just 2.60% might break even after costs.

Case Study: S$50,000 OA into a 6-Month T-bill (May 2026)

An investor with an OA balance of S$75,000 earmarks S$50,000 for the 15 May 2026 auction. The non-competitive bid is filled at the cut-off yield of 3.85%. On issue date (20 May), OA is debited S$49,057.50. She pays a one-time application fee of S$2.00 (OCBC) and two quarterly service fees totalling S$4.00. At maturity on 16 November 2026, S$50,000 is credited back to her OA. Gross profit: S$942.50; costs: S$6.00; forgone OA interest over six months (on the dynamic CPF balance) roughly S$618. Net gain: S$318.50, or an annualised net return of approximately 3.72% on invested capital—147 basis points above the OA rate.

FAQ

Can I use CPF Special Account (SA) savings for T-bills?
Yes, SA balances above S$40,000 are investible under CPFIS. But the SA floor rate is 4.00% (2026), while 6-month T-bill yields have been below 3.90% all year. Using SA would actually destroy value, making it an inferior choice.

How quickly do proceeds return to my CPF account after maturity?
On the maturity date, the face value is automatically credited to your CPF OA the same day if it falls on a business day. If it’s a weekend or public holiday, credit happens the next business day. CPF interest resumes from the date of credit.

What minimum investment is required?
The auction minimum is S$1,000 face value, in multiples of S$1,000. Your CPF OA must also have at least S$20,000 in balances you are not investing, leaving only the surplus available. For a single T-bill purchase, you’d need an OA balance of S$21,000 or more.

Are there any tax implications?
No. Gains on Singapore government securities are tax-exempt, and CPF withdrawals for investment are not taxable events.

References

• Monetary Authority of Singapore, 2026 – T-bill auction results and issuance calendar
• CPF Board, 2026 – CPF interest rate methodology and CPFIS rules
• DBS Bank, 2026 – CPF Investment Account fee schedule
• OCBC Bank, 2026 – CPFIS processing charges
• Singapore Government Securities, 2026 – T-bill information memorandum

This article does not constitute financial advice.