Mercury vs Rho for Startups (2026): Fees, Treasury Yield and Cashback by Stage

Mercury and Rho are built the same way: no account fee, $0 domestic wires, ACH and checks, 1% to convert currency, and a government money market fund for cash you do not need this month, with the same 0.60% to 0.15% fee scale. Pick Rho if you hold between $50,000 and $250,000 of idle cash, because Rho Treasury starts at $50K and Mercury Treasury at $250K, or if you can run payroll, revenue and most of your cash through Rho to earn its 2% Platinum cashback. Pick Mercury if you want same-day access to the fund, a 1.5% card with no conditions, or up to $5M of FDIC sweep coverage on checking. Above $250K the yields sit within 0.1 point of each other.

What each costs at pre-seed, seed and Series A

Same activity profile as our other banking comparisons (our assumption): pre-seed $500K cash ($150K operating), 2 domestic wires, 1 non-USD payment of $3,000 and $4,000 card spend a month (10% non-USD); seed $3M ($500K operating), 6 wires, 4 x $6,000, $20,000 card; Series A $12M ($2M operating), 15 wires, 12 x $10,000, $80,000 card (15% non-USD). Yield is earned on cash above operating needs, in each provider's government money market fund (Mercury MRGXX, 7-day effective SEC yield as of October 19, 2026; Rho IJTXX, 7-day SEC yield as of October 21, 2026), net of each provider's fee. Cashback is counted on USD card spend only (our simplification; Rho excludes non-US transactions). Rho publishes no fee for non-USD card spend, so its totals leave it out; Mercury charges 3%.

Read the table as a tie above $250K. The yield gap is 0.08 points at every stage, and Mercury's 3% card FX fee cancels most of it if your team pays for tools or ads in euros or pounds. The cases where one clearly wins sit below and beside the table: how much idle cash you have, and whether you can meet Rho's Platinum conditions.

Published prices

Prices verified on mercury.com/pricing on October 23, 2026.

Prices verified on rho.co/pricing on October 23, 2026.

Six things that decide it

1. Idle cash between $50K and $250K

This is the clearest difference. Rho Treasury opens at $50,000; Mercury Treasury needs $250,000 across your Mercury accounts. A company holding $200,000 it will not spend for a few months earns about $6,440 a year at Rho's 3.22% and nothing in Mercury Treasury. Mercury publishes no interest rate on its checking or savings accounts.

2. Three Treasury options vs two

Rho now lists three places to put the money: IJTXX, a JPMorgan government money market fund (3.22% net under $2M), MULSX, a Morgan Stanley ultra-short income fund (3.42%), and 13-week Treasury bills (3.54%), with allocations in 5% steps. Mercury offers MRGXX, a State Street government money market fund (3.30%), and MCRYX, an ultra-short bond fund (3.63%), which Mercury says "is not a money market fund". Ultra-short funds and T-bills pay more because they carry more price risk or less liquidity. All of it is SIPC-protected securities, not FDIC-insured deposits.

3. Getting the money back

Mercury describes MRGXX as same-day liquidity and MCRYX as 1 to 2 days. Rho says T-bill sales and fund redemptions settle in 2 business days when submitted before the daily cutoff (5:00 PM ET for T-bills, 4:00 PM ET for funds) and that proceeds reach checking within 2 business days. If payroll depends on moving cash out of the fund, Mercury is a day faster.

4. Card cashback and its conditions

Mercury's IO card pays 1.5% on settled purchases with no qualifying conditions; it is cash-underwritten, so your limit tracks your Mercury balance. Rho's corporate card pays up to 1.25% on Daily Terms or 1% on Monthly Terms, and up to 2% (1.75% monthly) with Rho Platinum, on up to $1M of eligible spend a year. Rho's card page says Platinum "applies when payroll is funded from Rho, revenue is deposited via Rho, 50% or more of company assets are held at Rho, and the company has an open Rho Corporate Card". It has no fee and no application. Rho forfeits cashback if the full statement balance is not paid on time and pays none on non-US transactions; Mercury pays none on its 3% FX fee.

5. FDIC coverage

Mercury offers up to $5M through its partner banks' sweep networks. Rho checking is covered up to $250,000 through Lead Bank (pass-through, "not automatic"), and its separate Business Savings account offers up to $75M through American Deposit Management Co. and its partner banks, which Rho calls program capacity on a best-efforts basis, not a guarantee. Rho Savings paid up to 1.00% APY from a $25,000 average balance (rate as of August 2026). Both are fintechs, not banks; Mercury has preliminary conditional OCC approval for Mercury Bank, N.A. (April 24, 2026), not yet open.

6. Who can open an account, and what else comes with it

Rho needs a US-incorporated company with a US address or one US-based owner with an SSN. Mercury's Treasury page lists 12 countries where the business may be located and excludes owners in "certain restricted countries". On extras, Mercury now lists two paid add-ons on its pricing page: Mercury Books at $35 a month and Mercury Payroll at $100 a month plus $50 per person paid, both waived until December 31, 2026. Rho includes bill pay, expense management and invoicing at $0 and offers incorporation and a SAFE note generator.

Recent changes

• Mercury (October 2026): Mercury Payroll appeared as an add-on, which was not on the pricing page when we read it on October 13. Treasury net yields rose to 3.30% to 3.75% in MRGXX.
• Rho (October 2026): the Treasury page now shows the money market fund, the ultra-short fund and T-bills side by side by balance tier; IJTXX net yield 3.22% under $2M (was 3.20% on October 9).

Switching cost

Neither charges to open or close an account. The work is operational: new account and routing numbers for customers paying you by ACH or wire, payroll and bill-pay links, a new card on every subscription, and accounting feeds. Treasury positions must be sold back to cash first. If you move to Rho for Platinum, payroll and revenue have to move too, so plan it around a payroll date.

Not hands-on tested yet: we have not opened an account with Mercury or Rho, which requires a US company and identity checks. Fees, yields and conditions come from Mercury's and Rho's pricing, Treasury and card pages, read on October 23, 2026. Yields change daily.

Frequently asked questions

Is Rho better than Mercury?

For most venture-backed startups holding over $250K the cost is nearly the same. Rho is better if your idle cash is between $50K and $250K or you can qualify for Platinum cashback; Mercury is better if you want the simpler 1.5% card, same-day fund access and more FDIC sweep coverage.

Does Rho or Mercury pay interest on checking?

Neither publishes a checking interest rate. Rho Savings paid up to 1.00% APY from $25,000 (as of August 2026). Both pay their higher yields through Treasury products that hold funds or T-bills, which are not bank deposits.

What is the minimum for Rho Treasury and Mercury Treasury?

Rho Treasury needs $50,000. Mercury Treasury needs $250,000 across all your Mercury accounts. Both charge an annual fee from 0.60% under $2M down to 0.15% at $20M or more, already taken out of the yields they show.

Which has the better corporate card?

Mercury's IO card pays 1.5% with no conditions but charges 3% on non-USD purchases. Rho pays 1.25% standard or 2% if payroll, revenue and at least half your assets are at Rho, has no personal guarantee, and publishes no card FX fee.

Related: startup banking costs by stage, Mercury vs Relay, Mercury alternatives, Mercury pricing, banking cost calculator, cash runway.