Mercury vs Brex: which startup account fits you?
Mercury and Brex both give startups a free business account, with deposits held at partner banks and spread across networks of banks for multi-million FDIC coverage. The differences that matter are in three places: when your idle cash starts earning, who each account is built for, and what you pay for extra features.
The short answer
- Brex fits better if you keep less than $250,000 of idle cash and want it to earn: Brex Treasury has no minimum and its yields start at 4.01%, while Mercury Treasury opens only above $250,000. Brex describes its account as a fit for startups that have raised or plan to raise funding, and for established growing companies.
- Mercury fits better if you send wires often: domestic wires, USD international wires and ACH transfers are free and the prices are published. Its paid plans add invoicing features and, on Pro, a relationship manager.
Side by side
| Mercury | Brex | |
|---|---|---|
| Monthly fee | $0 (Plus $29.90, Pro $299) | $0 for the account; spend management Premium is $12 per user per month |
| Minimum balance | None | None |
| FDIC coverage on deposits | Up to $5M through partner banks and sweep networks | Up to $6M through partner banks |
| Bank holding deposits | Choice Financial Group and Column N.A. | Column N.A. (checking) |
| Treasury minimum | Balances over $250,000 across Mercury accounts | No minimum deposit |
| Treasury yield | 3.32%–3.82% at $250K–$2M; targets up to 4.21% above $20M (net of fees, as of Nov 6, 2026) | 4.01% (up to $500K) to 4.36% ($20M+); date not shown |
| Treasury provider | Mercury Advisory LLC, an SEC-registered investment adviser; SIPC | Brex Treasury LLC, a broker-dealer, member SIPC |
| ACH | Free | Unlimited free same-day ACH |
| Wires | Domestic and USD international free ($15 with the OUR option); 1% FX fee on non-USD wires | Domestic wires included; the fee is not shown on the account page |
Read on November 13, 2026 from each company's pricing, account and treasury pages. Treasury products are investments, not deposits.
Yield on idle cash: the biggest difference
Mercury Treasury is available only when your balances across Mercury accounts are above $250,000. It invests in two mutual funds and individual US Treasuries through Mercury Advisory LLC. On November 6, 2026 it showed net yields of 3.32% to 3.82% for balances between $250,000 and $2M, depending on the option, and it targets up to 4.21% for balances above $20M. Its fee of 0.15% to 0.6%, depending on total deposits, is already subtracted from those yields.
Brex Treasury has no minimum deposit. It invests in the Dreyfus Government Cash Management Fund through Brex Treasury LLC, and Brex's chart runs from 4.01% for balances up to $500,000 to 4.36% above $20M. The page does not say which date those yields refer to.
In practice: a startup holding $150,000 can put idle cash into Brex Treasury, but not into Mercury Treasury.
Neither treasury product is a bank deposit. Both are covered by SIPC rather than the FDIC; Mercury states that SIPC protects up to $500,000 of securities and cash, of which up to $250,000 in cash. Funds are not guaranteed and their value can change.
FDIC coverage
The FDIC insures $250,000 per depositor, per bank, per ownership category. Both companies spread larger balances across partner banks: Brex states up to $6M of coverage, Mercury up to $5M. That insurance pays out if a partner bank fails. In the FDIC's words, it "does not protect against the insolvency or bankruptcy of a nonbank company."
Fees and payments
Both base accounts are free, with no minimum balance. Mercury publishes the price of each payment. Domestic wires, USD international wires and ACH transfers cost nothing, and a non-USD wire carries a 1% currency exchange fee. Paying the recipient bank's fees on a USD international wire (the OUR option) costs a flat $15. Brex offers unlimited free same-day ACH and includes domestic wires; its wire fee is in a separate fee schedule, not on the account page we checked.
Paid plans cover different needs. Mercury Plus ($29.90 a month) and Pro ($299 a month) add invoicing features and support, with a relationship manager on Pro. At Brex, the paid tier is its spend management software: Essentials is $0 per user and Premium $12 per user per month.
Who each account is built for
Brex says its business account is "a great fit for startups who have or are planning to raise funding and for established growing companies." Capital One completed its acquisition of Brex on April 7, 2026, and Pedro Franceschi continues as Brex's CEO.
Mercury describes itself as "a fintech company, not an FDIC-insured bank"; its banking services are provided through Choice Financial Group and Column N.A. Its pricing page does not describe a funding requirement.
Which should you choose?
- Choose Brex if you have raised or plan to raise money, you want yield on cash below $250,000, or you want the highest stated FDIC coverage ($6M).
- Choose Mercury if you send domestic or USD wires abroad regularly, you want every payment fee published upfront, or you need invoicing features.
- Consider both. Any bank or platform can freeze an account during a compliance review; a second account at another provider keeps payroll running if that happens.
For Relay, Bluevine and Novo as well, see our comparison of five startup bank accounts.
Frequently asked questions
Are Mercury and Brex banks?
Mercury states that it is "a fintech company, not an FDIC-insured bank," with banking services provided through Choice Financial Group and Column N.A. Brex says its checking deposits are held at its partner bank, Column N.A.
Is money in Mercury Treasury or Brex Treasury FDIC insured?
No. Both are investment accounts covered by SIPC, not by FDIC deposit insurance.
Who owns Brex?
Capital One, which completed its acquisition of Brex on April 7, 2026.
How we compared
We read Mercury's pricing and treasury pages and Brex's business account and pricing pages on November 13, 2026, then checked every figure a second time. We have not opened test accounts with either company and we do not score customer service, which we cannot measure.
Some links on this site may earn us a commission if you open an account. That does not change the facts above. How we make money.
This page is general information, not financial, legal or tax advice. Best Bank for Startups is not a bank and is not affiliated with Mercury or Brex.