TribeCar + Trust Bank + Endowus + IBKR: The Achievable-Rate Funding Ladder (2026)

Not financial advice. This is one way to sequence four accounts, not a recommendation for your situation.

Skip car ownership with TribeCar and you free up roughly S$1,000 to S$1,500 a month once you count COE, insurance, petrol, parking and servicing. Where that cash goes next matters more than how much of it there is. This combo orders it by how certain each dollar’s return actually is: Trust Bank’s achievable (not headline) savings rate first, Endowus SRS tax relief second, IBKR’s uncapped market growth last.

Five 4-way combos already exist on this site: floor-vs-flex bonus placement (Trust Bank + GXS + FSMOne), an SDIC protection-tier waterfall (MariBank + Syfe + IBKR), a tax-relief cap sequence (Endowus + FSMOne + IBKR), months-of-expense liquidity tiering (GXS + Endowus + Syfe), and a trade-size fee-structure threshold (FSMOne + GXS + Syfe). This one is new: it ranks each destination by how achievable its promised return is, not by its cap size, insurance status or fee structure.

Why this combo is different

Most of the site’s earlier combos rank money by cap size, insurance coverage or fee structure. This one ranks by certainty. A bank’s advertised savings rate, a scheme’s tax relief and a brokerage’s market return are not the same kind of promise. One is achievable this month with no lock-in. One is guaranteed once you file taxes, but only up to a hard annual cap. One has no cap and no guarantee at all, just whatever the market does.

Fund the achievable one first. Cap out the guaranteed one second. Let the uncapped, uncertain one take whatever is left.

The reasoning holds up under a simple test: what happens if you stop contributing halfway through the year? Trust Bank’s scoops reset monthly, so a missed month just means one month at 0.05% instead of 0.85%, no permanent damage. Endowus SRS relief is use-it-or-lose-it each calendar year; contribute S$8,000 instead of the full S$15,300 and you only get relief on the S$8,000, the unused S$7,300 of cap does not carry forward. IBKR has no schedule at all, you buy when you have spare cash and skip when you do not. Ranking by certainty also means ranking by how forgiving each step is if your monthly TribeCar savings vary, which they will.

Step 1: Trust Bank Flex — the achievable rate

Trust Bank’s Flex plan advertises up to 2.40% p.a. That figure needs S$20,000 in new TrustInvest fund purchases, a S$100,000 average daily balance, or a successful credit card referral in the same month. None of those fit a TribeCar-freed cash buffer of S$1,000 to S$1,500.

Three scoops do fit. Credit at least S$1,500 salary via GIRO each month for +0.45% p.a. Make five card spends of at least S$30 each for +0.20% p.a. as an NTUC union member (+0.10% if you are not). Receive at least S$1,500 in incoming PayNow transfers for +0.15% p.a. Stack those on the 0.05% p.a. base rate and you land at 0.85% p.a. as a union member, 0.75% p.a. otherwise. No investing, no six-figure balance, no referral needed.

Step 2: Endowus SRS — the guaranteed tax relief

Once the Trust Bank buffer is running, the next dollar goes to Supplementary Retirement Scheme contributions invested through Endowus. Every dollar you put into SRS, up to S$15,300 a year for citizens and PRs (S$35,700 for foreigners), reduces your chargeable income by that same dollar. On a S$100,000 income with typical personal reliefs, maxing the SRS cap can cut roughly 48% off the tax bill, a guaranteed outcome the moment you file, regardless of what markets do afterward.

Left in the default SRS bank account, that money earns 0.05% p.a. Endowus routes it into Cash Smart instead, targeting 1.3% to 2.5% p.a. depending on risk tier. That yield is not guaranteed and moves with rates; the tax relief is the part that is fixed the moment you contribute.

Step 3: IBKR — the uncapped overflow

Anything left over goes to IBKR for global equities, with no bonus rate and no tax relief attached. It is worth knowing that idle cash sitting there earns nothing at the small balances this combo produces: SGD deposits pay 0% p.a. below S$14,000, and USD deposits pay 0% p.a. below US$10,000. That is fine here, because this step is for buying investments, not for parking cash. Uninvested overflow should move straight into a position rather than sit in the account.

This is also the step with no floor. Trust Bank guarantees 0.85% p.a. on the scoops you hit. Endowus guarantees the tax relief the moment you contribute. IBKR guarantees nothing; a global equity portfolio can be down in any given year, and the money here has no lock-in cushion or relief to fall back on if markets turn. That is the tradeoff for having no cap: more of the eventual outcome, but none of the certainty the first two steps provide.

The funding ladder in one table

How this compares to the other four-way combos

The first 4-way combo, Trust Bank + GXS + FSMOne, compares where a bank’s bonus interest applies, locked tranche versus whole balance. The third, Endowus + FSMOne + IBKR, ranks tax-relief caps against each other before letting IBKR take the overflow. This combo sits between the two ideas: it puts a bank’s real, achievable savings rate ahead of any tax-relief step, then lets the relief cap run before the uncapped market leg. Read together, they cover savings-rate honesty, tax-relief sequencing and now the order in which the two should be funded relative to each other.

This is not financial advice. Rates, caps and thresholds change; verify current figures directly with Trust Bank, Endowus, IBKR and TribeCar before acting. Figures in this article were verified against trustbank.sg, endowus.com and interactivebrokers.com.sg on 16 September 2026.