Relay and Mercury are both business banking platforms aimed at small businesses, but they serve meaningfully different use cases. Relay emphasizes multi-account cash organization and bookkeeper access. Mercury emphasizes startup-friendly features like a corporate charge card, treasury tools, and API access.
This comparison documents each platform’s structure, fees, and constraints symmetrically.
At a glance
- Relay: Best-suited for cash-management-focused small businesses; up to 20 accounts and 50 debit cards; no corporate card.
- Mercury: Best-suited for startups and growth-stage companies; fewer accounts but adds a charge card, treasury, and software integrations.
How the products compare structurally
| Dimension | Relay | Mercury |
|---|---|---|
| Banking partner | Thread Bank | Evolve Bank & Trust, Choice Financial Group |
| Bank charter held | No | No |
| FDIC insurance | $250K standard | Up to $5M via sweep |
| Checking accounts per business | Up to 20 | Typically 1 per entity |
| Debit cards | Up to 50 | Standard debit cards |
| Corporate charge card | No | Yes (Mercury IO) |
| Treasury / yield product | No (Pro savings only) | Yes (Mercury Treasury) |
| Bookkeeper access | Yes (dedicated permission model) | Limited multi-user access |
| Monthly fee | None (standard), $30 (Pro) | None (standard), $35 (Plus), $350 (Pro) |
| API access | No | Yes (higher tiers) |
How each product is structured
Relay
Relay provides up to 20 individual checking accounts under a single business relationship, each with its own account and routing number. This structure supports operational segmentation — separating tax reserves, operating funds, payroll, and savings into discrete accounts without maintaining multiple banking relationships.
Each account can have dedicated debit cards, and up to 50 physical or virtual cards can be issued across the business. Cards are configurable with per-card spending limits that can be updated in real time.
Bookkeeper access is a core feature. External accountants and bookkeepers can be invited to view or manage accounts with granular permissions, without sharing the primary business owner’s login.
Relay does not provide a corporate charge card, treasury investment product, or API integration.
Mercury
Mercury provides a business checking account, a savings account, and an optional charge card (Mercury IO) under a single entity relationship. The platform also offers Mercury Treasury, a product that routes idle cash into government money market funds to earn yield.
Multi-user access is available, though the permissions model is less granular than Relay’s bookkeeper-specific roles. Mercury’s API allows businesses to programmatically initiate payments, retrieve transactions, and manage account data.
Mercury also provides a sweep-based FDIC coverage structure that can extend insurance to up to $5 million — a meaningful differentiator for startups holding large cash reserves between funding rounds.
Fees and pricing mechanics
Both Relay and Mercury offer free standard tiers with no monthly fees, no minimum balances, and no ACH fees.
Relay charges approximately $5 per outgoing domestic wire at the standard tier. Mercury includes free domestic wires for standard accounts. Both charge for outgoing international wires, though the structure differs by tier.
Relay Pro ($30/month) adds a yield-bearing savings account and priority support. Mercury Plus ($35/month) and Mercury Pro ($350/month) add higher wire limits, dedicated support, API rate increases, and advanced user management.
Limits, eligibility, and availability
Both platforms accept the same range of U.S. business entity types: sole proprietors, LLCs, S-corps, and C-corps. Non-U.S. founders with U.S.-incorporated companies can access Mercury but not Relay.
Both platforms are fully digital with no branch access. Customer support at standard tiers is asynchronous for both, with paid tiers offering faster response.
Neither platform provides credit products at their free tiers. Relay offers none at any tier. Mercury’s charge card is available at the standard tier, with limits tied to the deposit balance.
Tradeoffs and constraints
Relay is optimized for businesses that prioritize cash organization, bookkeeping transparency, and managing employee spending without a formal corporate card program. The multi-account structure is its primary differentiator. However, it earns no yield on operating cash at the free tier and has no charge card.
Mercury is more feature-rich on the financial products side: a charge card, treasury yield, API access, and higher FDIC sweep coverage. The tradeoff is a simpler single-account deposit structure, which is less suited to businesses that rely on segregated cash management.
For small businesses choosing between the two, the decision often turns on the primary need: if the priority is organizing cash flows and giving bookkeepers clean access, Relay is the more focused tool. If the priority is maximizing idle cash yield or accessing a corporate card alongside banking, Mercury addresses those needs directly.
See also: Bluevine Review for a small business alternative with high-yield checking and an optional credit line.
