Side-by-side
| Dimension | Mercury | Brex |
|---|---|---|
| Eligibility | Any non-resident LLC at any stage | VC-funded ($1M+) or $100K+ revenue typical |
| Non-resident approval rate | ~70% | Uneven, often rejected for early-stage non-residents |
| Monthly fee | $0 | $0 |
| Credit cards | Debit only (up to 50, spend controls) | Corporate credit cards, $50K-$1M+ limits for qualified startups |
| Treasury yield | Yes, T-bill sweep with FDIC up to $5M | Yes, Brex Cash sweep to government securities |
| Approval time | 1-7 business days | 1-3 business days for qualifying applications |
| Best fit | Any non-resident LLC at formation or early growth | Funded startups with $100K+ revenue or VC backing |
When Mercury wins
- You are pre-revenue, bootstrapped, or under $100K annual revenue
- You do not have VC funding
- You are non-resident with a non-US-resident operating profile
- You want one consolidated US business bank covering ACH, wires, debit cards, and Treasury
- You prioritize uniform approval over high credit limits
When Brex wins
- Your LLC has $100K+ annual revenue or raised $1M+ in priced equity
- You spend heavily on ads, SaaS, or operating costs and want corporate credit limits in the $50K-$500K range
- You qualify for Brex Rewards (higher cashback tiers than debit cards)
- You want spend management software bundled with the card program
Brex eligibility, honestly
Brex's underwriting is built around high-growth US startups with predictable revenue or institutional funding. Brex does not publish a hard cutoff, but our intake confirms the practical floor: $100K trailing twelve-month revenue, or a priced equity round of $1M+, with strong preference for US-resident founders or US-based operating teams.
Brex acknowledges this directly. They state that they serve startups in growth mode rather than every small business. Bootstrapped solo operators are not the target. This is a clear positioning call by Brex, not a flaw.
Migration path: Mercury first, Brex later
- Open Mercury at formation. Run all banking, Stripe payouts, and debit-card spend through Mercury for the first 12 months.
- Build revenue history. Track monthly recurring revenue or trailing revenue documentation.
- Once you cross $100K annual revenue, apply to Brex. Brex underwriting considers your Mercury history and Stripe revenue.
- Maintain both: Mercury for ACH, wires, and Treasury yield. Brex for credit lines on ad spend and operating costs.
Application requirements
- Mercury: Articles, EIN letter, passport, business description, anticipated transaction volume
- Brex (same as Mercury) plus: revenue documentation, bank statements (often Mercury), Stripe dashboard screenshot, or funding documents
- Both accept remote applications. Brex prefers a US-based principal or operating presence.