Startup Banking Cost Calculator

Fees and yield at pre-seed, seed and Series A

Our assumptions, not vendor data: cash $0.5M / $3M / $12M with $150K / $500K / $2M kept for operations; 2 / 6 / 15 domestic wires and 1 / 4 / 12 non-USD payments a month ($3K / $6K / $10K each); card spend $4K / $20K / $80K a month, 10% / 10% / 15% of it non-USD. Fees = plan, wires, FX on payments, card FX. * = the vendor does not publish a fee this activity needs (FX on international payments for Brex, Ramp and Chase; card FX for Rho), so the figure leaves it out. Yields are the published rates on the dates shown in the calculator.

Two things stand out. Fees are small and yield is large: at seed, the accounts that publish every fee charge about $3,600 to $6,600 a year, mostly currency conversion on international payments, while cash earns from nothing (Chase) to over $90,000 depending on where it sits. And the yields are not the same product: Relay, Bluevine and Ramp pay interest on FDIC-insured deposits; Mercury, Rho and Brex invest idle cash in government money market funds, which are not FDIC-insured (Brex and Rho keep them in brokerage accounts covered by SIPC, which does not protect against a fall in value).

Is my money safe at a fintech bank?

Mercury, Relay, Brex, Ramp, Novo and Bluevine are not banks. Your deposits sit at partner banks (for example Choice Financial Group and Column N.A. for Mercury, Thread Bank for Relay, Coastal Community Bank for Bluevine), and the FDIC says plainly that "nonbank companies themselves are never FDIC-insured". Your money is insured through the partner bank only if the records show who owns it and how much, and FDIC insurance "does not protect against the insolvency or bankruptcy of a nonbank company".

That gap is what hurt Synapse customers. Synapse, a middleware company between fintech apps and their banks, filed for bankruptcy on April 22, 2024; its trustee later reported a shortfall estimated at $65 to $96 million between what customers were owed and what the banks held. No bank failed, so deposit insurance did not pay. The FDIC proposed a recordkeeping rule for custodial accounts in October 2024; as of today it is neither final nor withdrawn.

"Up to $5M" (Mercury) or "$3M" (Relay, Bluevine) of FDIC coverage comes from sweep networks that split your balance into pieces under $250,000 at many banks. The coverage is real but depends on the vendor keeping accurate records. Mercury received preliminary conditional approval for its own national bank charter from the OCC on April 24, 2026; it is not open yet. Brex has been part of Capital One since April 7, 2026.

Frequently asked questions

What is the cheapest bank account for a startup?

On fees alone, the free plans of Mercury, Rho and Brex charge nothing for domestic wires, and Ramp charges nothing when you pay from Ramp Checking. The real differences are currency conversion on international payments (1% at Mercury and Rho, as little as 1% at Relay, 0.5% for major currencies at Airwallex) and card foreign transaction fees (3% at Mercury, up to 3% at Brex and Ramp, 1% at Relay; no fee of their own at Bluevine or Novo, and "zero international fees" on Airwallex cards).

Which startup bank pays the highest interest?

Among the rates in the calculator, the money market products of Brex, Mercury and Rho pay roughly 3.2% to 3.9% depending on balance, and Bluevine Premier pays 3.0% on FDIC-insured checking. Rates change often; each one in the calculator carries its as-of date.

Are money market funds safe for startup cash?

Government money market funds hold short-term government debt and aim for a stable $1.00 share price, but they are not bank deposits: the SEC's investor site notes they are not FDIC-guaranteed and you can lose money. SIPC protects up to $500,000 if a broker fails, not against a fall in value.

Do business accounts get the same fraud protection as personal accounts?

No. Regulation E's error-resolution rules cover accounts held "primarily for personal, family, or household purposes", so business checking disputes run under the account agreement and card-network rules.

Idle cash yield is part of your runway. To see it next to burn, hiring and revenue, model it in Adlega.