The Mercury IO card is the credit card built into Mercury’s business banking platform — and it is one of the simplest 1.5% cashback cards for startups and small businesses. In this 2026 review we cover the rewards, fees, limits, who it is for, and how it compares. Plus, right now you can stack it with a welcome offer worth up to $375.
💳 Get the Mercury IO Card + Up to $375
Open Mercury, get the IO card on day one with 1.5% unlimited cashback, and earn up to $375 in welcome bonuses.
Mercury IO Card at a Glance
| Cashback | 1.5% unlimited on all spend |
| Annual fee | $0 |
| Availability | Day one of opening a Mercury account |
| Cards | Virtual + physical, for the whole team |
| Issuer | Patriot Bank, N.A. (Mastercard) |
| Controls | Per-card limits and spend rules |
The Rewards: 1.5% on Everything
The IO card earns 1.5% unlimited cashback on all spend — no categories to track, no caps. Cashback is credited to your Mercury account automatically. To keep earning, your Mercury accounts must be open and in good standing.
Fees and Costs
There is no annual fee. Because the IO card is tied to your Mercury balance and cash flow rather than a traditional revolving line, it keeps things simple for businesses that pay in full.
Team Spend Controls
You can issue virtual and physical cards to team members with individual limits and spend rules, then track everything in the Mercury dashboard. This is a big advantage over a personal card for expense management.
Who the IO Card Is Best For
- Startups and small businesses that want simple flat-rate cashback.
- Teams that need multiple cards with controls.
- Founders already using (or opening) Mercury for banking.
Verdict
For businesses banking with Mercury, the IO card is a no-brainer add-on: 1.5% back on everything, no annual fee, and available immediately. Pair it with the current welcome offer and you can earn up to $375 in your first 90 days.
FAQ
Does the IO card have an annual fee?
No — $0 annual fee.
When can I get the IO card?
From day one of opening your Mercury account.
How is cashback paid?
Automatically to your Mercury account, as long as it is open and in good standing.
Ready to Try the Mercury IO Card?
1.5% cashback, no annual fee, and available from day one. Open Mercury and start earning.
Affiliate disclosure: We may earn a commission if you open a Mercury account through links on this page, at no cost to you. Mercury is a financial technology company, not a bank; the IO Card is issued by Patriot Bank, N.A., Member FDIC, pursuant to a license from Mastercard. This is not financial advice.