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Mercury vs Brex (2026): Business Banking and Startup Cards Compared

Updated October 2026 · 8 min read

Mercury and Brex are the two names that come up in almost every startup finance conversation, and they solve the problem from opposite ends. Mercury starts with banking and adds a card. Brex starts with the corporate card and spend management, then adds banking around it. Both skip the personal credit check, both are free to start, and both target venture-backed and growing startups rather than brick-and-mortar small businesses. Here is how they actually compare.

1. Mercury: banking first, with a built-in card

Mercury is a digital-first business banking platform for startups and e-commerce businesses. The free tier includes business checking and savings, debit cards, ACH transfers, free domestic wires, and virtual cards, with no monthly fees and no minimum balance requirements. Deposits are held through partner banks (Choice Financial Group and Column N.A.) with up to $5 million in FDIC insurance through their sweep networks. More than 300,000 businesses use Mercury, per the company's own site.

The Mercury IO card is not a separate product you apply for. It is bundled into Mercury banking: once your account is open, eligible customers get a charge card with unlimited 1.5% cashback on all spend, no annual fee, no personal guarantee, and no credit check. The credit limit is based on your total Mercury balances and any external accounts you link, so it scales as your cash grows. New customers with lower balances start on daily repayment terms; once balances reach $15,000 you can switch to 30-day terms. It reports to business credit bureaus and syncs with QuickBooks, Xero, and NetSuite. Mercury also offers Mercury Treasury, an automated cash management account that puts surplus balances into money market funds for yield; Treasury access has historically required around $250,000 in deposits.

Watch for: Mercury does not accept sole proprietors or trusts, even with an EIN. International wires are not all free: domestic wires are $0, but international wires run $15 flat plus a 1% FX fee on non-USD transfers, per third-party fee schedule reviews. Treasury yield is variable and moves with interest rates, so treat published APY figures as snapshots. The IO card is a charge card, so you pay in full every period, and there are no category multipliers if your spend is heavy on SaaS or travel.

2. Brex: card-first, with banking built in

Brex is a corporate card and spend-management platform that also offers business banking, bill pay, reimbursements, and travel in one dashboard. The card runs on the Mastercard network, requires no personal guarantee and no personal credit check, and comes with tiered rewards: 7x on rideshare, 4x on Brex travel (flights and prepaid hotels), 3x on restaurants, 2x on recurring software, and 1x on everything else, per Brex's own site. Rewards can be redeemed for cash back, travel, and other options. One caution: third-party reviews report that Brex points were devalued so that cash back is worth roughly 0.6 cents per point rather than the old 1 cent, which drops the effective general-spend cashback well below the headline multipliers.

Pricing is straightforward. Essentials is $0 per user per month, and most startups stay on it: it includes global Brex cards, reimbursements, travel booking, local-currency wires, real-time reporting, standard accounting integrations (QuickBooks, Xero, NetSuite), and basic spend controls. Premium is $12 per user per month and adds custom roles, live budgets, VAT documentation, and deeper ERP integrations. Enterprise is custom-priced. Brex's business account is free to open with no minimum deposit, advertises $0 transfer fees and a yield on Treasury cash, and offers up to $6 million in FDIC coverage through its partner bank, Column N.A. In January 2026, Capital One announced it would acquire Brex for $5.15 billion, and the deal closed in April 2026, which means future pricing and product structure are worth watching.

Watch for: Brex has a real eligibility gate. It targets companies with equity funding, roughly $500,000 or more in annual revenue, or about $50,000 in cash for funded startups; sole proprietors and general partnerships are not accepted, and meeting the requirements does not guarantee approval. International card transactions carry an FX markup reported at up to roughly 3%, and some cross-border payments or advanced workflows can carry additional fees.

3. Fees side by side

MercuryBrex
Monthly account fee$0 (free tier), no minimums$0 (Essentials)
Paid plansMercury Plus (paid tier; reported roughly $30-$35/mo), Pro customPremium $12/user/mo, Enterprise custom
Domestic wires$0Reported $0 out
International wires$15 flat plus 1% FX on non-USDLocal-currency wires included on Essentials; fees may apply to some cross-border payments
Card annual fee$0 (IO card)$0 (Brex corporate card)
FX on card spend1.5% cashback applies to international spend tooUp to ~3% FX markup on international card transactions

Fee figures are snapshots from provider pricing pages and third-party fee reviews, and they change. Always confirm the current schedule before you commit.

4. Card rewards: flat versus tiered

This is the cleanest contrast in the comparison. Mercury IO pays a flat, unlimited 1.5% cashback on everything, automatically deposited into your account, with no points to value and no categories to track. Brex pays multipliers in the categories startups spend heavily in (7x rideshare, 4x Brex travel, 3x restaurants, 2x software) but 1x on everything else, and its points have been devalued for cash back, so the headline numbers overstate the real return on general spend. If your spend concentrates in Brex's bonus categories, Brex wins. If you want one predictable rate with zero tracking, Mercury wins.

5. Credit model: how limits are set

Neither company runs a personal credit check or asks for a personal guarantee, which is the whole point for founders who do not want company debt touching their personal credit. Mercury sets your IO limit from your total Mercury balances (plus linked external accounts), reassessing after large deposits and withdrawals. Brex underwrites the card against your business cash and revenue or funding, and explicitly says approval is not guaranteed even if you meet the published requirements. Practically: Mercury's limit grows and shrinks with your balance, while Brex's bar is getting approved in the first place.

6. Integrations and platform

Both integrate with the core accounting stack: QuickBooks Online, Xero, and NetSuite. Mercury adds an API that engineering teams like, expense-management tools with team cards and built-in controls, virtual cards on demand, and startup-specific touches like in-dashboard SAFE creation. Brex's differentiator is the spend-management layer itself: real-time spend tracking, auto-categorization, team-level budgets and policies, AI-assisted transaction coding, reimbursements, bill pay, and built-in travel booking. Brex also offers 24/7 live support on all tiers. If you want a bank with good tooling, Mercury has the edge. If you want a finance operating system for a growing team, Brex has the edge.

7. Who is each best for?

Mercury fits pre-seed to Series A startups that want free banking as the core product: no monthly fees, free domestic wires, virtual cards for SaaS spend, a simple 1.5% cashback card that appears automatically, and Treasury yield on idle cash. It is also friendlier to non-resident founders, with third-party reviewers reporting it approves the largest share of non-resident applications among US fintech banking platforms. Skip it if you are a sole proprietor, handle cash deposits, or want rich rewards categories.

Brex fits funded startups and mid-market companies that want a real corporate card program with spend controls, expense management, and travel booking in one place. The tiered rewards pay off if your team spends heavily on rideshare, travel, restaurants, and software. Skip it if you cannot clear the funding or revenue bar, want the simplest flat cashback, or do most of your card spend internationally, where the FX markup bites.

Our pick: Mercury for early-stage startups that want free, simple banking with a no-hassle 1.5% cashback card baked in. Brex for funded or revenue-generating companies that want a full spend-management platform and can actually use its category multipliers. They are not mutually exclusive: many startups bank with Mercury and run a second card platform on top for the features Mercury does not bundle.

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