Mercury vs Stripe for SMB invoicing. Both, used differently.
Most owners walk in trying to pick one. Most owners walk out using both, because Mercury and Stripe solve different halves of the same problem.
The question gets asked at least once a week in every founder Slack. "Should I invoice through Mercury or Stripe?" It sounds like a one-or-the-other call. It almost never is. After helping a couple dozen 1-to-50-person businesses set up their money plumbing, the pattern is consistent. Mercury runs the bank account, the ACH send-and-receive, and the bill pay. Stripe runs the card processing, the recurring subscriptions, and any invoice the customer is going to click and pay online with a card.
The interesting question is not which one. The interesting question is the split. Which customers go down which rail, what each one actually costs you per dollar collected, and where the reconciliation lives at the end of the month. Get that right and the monthly close stops being a thing you dread.
What each tool actually does
Mercury is a business bank. The account is free, with no minimums, no monthly fees, no account opening fees, and no overdraft fees1. You get a checking account, a savings account, virtual and physical debit cards, and a bill-pay surface. Domestic USD wires are free. International USD wires are free with standard processing. You can send money via ACH at no cost, and you can receive ACH, wires, and checks at no cost.
Mercury also has a built-in invoicing product that lets a customer pay you by ACH for $0 on the Pro plan, $1 per transaction on the Plus plan, and is included in the higher tiers1. If a customer pays a Mercury invoice with a card instead, that piece is actually processed by Stripe under the hood at 2.9% + $0.30. So even when you "stay inside Mercury," the card rail is Stripe.
Stripe is a payments processor. Standard US pricing is 2.9% + $0.30 per successful card charge for domestic cards, plus 0.5% for manually keyed cards, plus 1.5% for international cards, plus 1% if currency conversion is required2. ACH Direct Debit on Stripe is 0.8% capped at $5.00 per transaction. Stripe Invoicing adds 0.4% of the invoice total, capped at $2.00 per invoice, on top of the underlying payment fee2.
Stripe Billing handles subscriptions, dunning when a card fails, proration when a customer upgrades mid-cycle, and tax collection through Stripe Tax. That stack is what every SaaS company in the world uses for a reason. Mercury does not try to compete with it.
What it actually costs to collect a dollar
The fee math is where most owners pick wrong, because they compare list prices instead of effective costs on their real mix. A few concrete examples.
$5,000 B2B invoice, paid by ACH. Through Stripe: $5,000 × 0.8% = $40, capped at $5. Plus the 0.4% Invoicing fee, capped at $2. Total: $7. Through Mercury invoicing on the Pro plan: $0. Through Mercury invoicing on the free or Plus plan: $1 or less. If you send a lot of large B2B invoices, the gap is real. On a $50,000 month of ACH invoices, Mercury saves you somewhere between $60 and $70 a month on fees alone.
$200 consumer invoice, paid by card. Through Stripe: 2.9% + $0.30 = $6.10, plus 0.4% Invoicing = $0.80 (capped at $2 anyway), call it $6.90. Through Mercury: the same $6.10, because the card piece routes to Stripe. The Mercury wrapper does not save you anything on cards. If your customers want to click and pay with a card, you are paying Stripe rates either way.
$49 monthly SaaS subscription. Through Stripe Billing: 2.9% + $0.30 = $1.72 per charge, plus a small Billing fee depending on plan. Through Mercury: not really a fit. Mercury invoicing is not built for recurring card subscriptions with dunning, proration, and trial logic. This is Stripe's home turf.
The "both, used differently" pattern
Once the fee math is on the table, the split writes itself.
Mercury holds the money. Operating checking, tax savings sub-account, payroll funding account, anything you sweep into a treasury product. The debit card lives on Mercury. Vendor bill pay runs through Mercury (free ACH out, free domestic wires, scheduled and approval-routed).
Mercury invoices the B2B customers who pay by ACH. Anyone with a real AP department who is going to enter your routing and account number into their system, send you an ACH, and remit the invoice number. These are the invoices where Stripe's 0.8% (even capped at $5) is pure waste compared to Mercury's $0 to $1.
Stripe invoices the customers who want to click and pay with a card. Smaller invoices, faster turnaround, international customers, anyone who is going to put it on a corporate Amex for the points. The 2.9% + $0.30 is the cost of getting paid same-day instead of in two weeks. Often worth it.
Stripe runs the recurring revenue. Any subscription, any seat-based pricing, any usage-metered billing. Stripe Billing plus Stripe Tax is the standard for a reason. Trying to glue this together on top of Mercury invoicing is the kind of project that eats three weeks and breaks in month two.
The two systems meet in your accounting software. Stripe payouts land in your Mercury operating account by ACH on a rolling 2-day schedule (or daily, weekly, monthly depending on how you configure it). Mercury's QuickBooks Online integration and Stripe's QuickBooks Online integration both push transactions in cleanly with the original payer, invoice number, and fee broken out as a separate line. Reconciliation is a half-hour task at month end, not a half-day one.
When to choose only one
The "both" pattern is the default for most owner-operators, but there are two cases where one tool is actually enough.
Sub-$100K ARR, all card revenue, no B2B ACH. A consumer e-commerce shop, a one-person consultancy that charges by credit card, a SaaS at the seed stage. Just Stripe. Use Stripe Atlas or your existing bank for the underlying account, run all revenue through Stripe, payout to that account. Adding Mercury at this stage is a workflow you have to maintain for no real fee savings. Worth revisiting at $100K to $250K ARR when your first big ACH customer shows up.
Pure B2B services, all invoices over $2,000, all paid by ACH or wire. A consulting firm, a CPA practice, an agency where every customer has an AP department. Just Mercury. The Stripe rails are not adding anything you use. Mercury invoicing handles the ACH, the QuickBooks sync, and the bank account in one place. If a customer ever insists on paying by card, send them a one-off Stripe payment link from a free Stripe account and bill the card fee back to them, or eat the 2.9% as a cost of closing.
Everyone in between, which is most 1-to-50-person businesses, ends up running both.
Reconciliation reality
Two practical notes from setting this up in the wild.
Both Mercury and Stripe have native QuickBooks Online integrations that work. They both push transactions with the customer name, the invoice reference, and a separate line for the processor fee, which is what your bookkeeper actually needs to close the month cleanly. Xero integrations exist for both as well. If you are still on a desktop QuickBooks or a custom spreadsheet, this is the moment to migrate.
The one quiet trap is that Stripe payouts arrive in your bank account as a single net ACH deposit covering many individual charges, with the fees already netted out. If your bookkeeper books the deposit as revenue you will understate revenue and understate fees by the exact same amount. The QuickBooks integration handles the split automatically; a human entering bank feeds by hand often does not. Verify this once at month two of your setup and never think about it again.
Key takeaways
- Mercury and Stripe solve different problems. The smart move is to use both, with a clear split, not to pick one.
- Mercury for the bank account, vendor bill pay, and B2B ACH invoices (Pro plan = $0 per ACH invoice).
- Stripe for card-paid invoices, recurring subscriptions, and anything international (2.9% + $0.30 cards, 0.8% capped at $5 ACH, 0.4% capped at $2 Invoicing).
- Card payments on Mercury invoices are processed by Stripe under the hood at the same rate, so the wrapper saves you nothing on cards.
- Sub-$100K ARR with all-card revenue: just Stripe. Pure B2B services with all ACH revenue: just Mercury. Everyone else: both.
- Use the native QuickBooks Online integrations on both sides. Watch the Stripe net-payout trap at month two.
Sources
- Mercury. "Pricing." mercury.com, 2026. Banking services free with no minimums, monthly fees, or overdraft fees. Mercury Plus $29.90/mo, Mercury Pro $299/mo. ACH invoicing $1/transaction on Plus, $0 on Pro. Domestic wires free; international USD wires free with standard processing. mercury.com/pricing
- Stripe. "Pricing." stripe.com, 2026. Standard US card processing 2.9% + $0.30. Manually keyed cards +0.5%. International cards +1.5%. Currency conversion +1%. ACH Direct Debit 0.8% capped at $5.00. Stripe Invoicing 0.4% capped at $2.00 per invoice on top of the payment fee. stripe.com/pricing
- Stripe. "Invoicing." docs.stripe.com, 2026. Product documentation covering one-off invoices, subscription invoices, Stripe Billing, dunning, and Stripe Tax integration. docs.stripe.com/invoicing