Mercury vs Polar

Pricing

Mercury: Free for basic, paid tiers available

Polar: Free plan at 5% + 50c per transaction; Pro $20/mo at 3.8% + 40c

Description

Mercury: Banking built for startups

Polar: Open-source merchant of record for selling software, subscriptions and usage-based billing, handling sales tax for you

Pros

  • Beautiful UI
  • Fast account opening
  • Good for bootstrapped + VC-backed
  • Acts as merchant of record: it collects and remits sales tax and VAT on your sales
  • Usage billing, subscriptions and credits can be combined on one product, which suits AI products billed by tokens
  • Open source under the Apache 2.0 licence

Cons

  • US-focused
  • Not a full bank (partner bank model)
  • Fees are higher than a plain payment processor: 5% + 50c per transaction on the free plan, plus 1.5% for non-US cards
  • Disputes cost $15 each whatever the outcome, and transaction fees are not returned when you refund
  • Payouts carry Stripe's charges: $2 a month while payouts are active, plus 0.25% + 25c per payout

Details

Mercury is banking that doesn’t suck. Founded by Immad Akhund, designed specifically for startups. Clean interface, fast onboarding, serves both VC-backed and bootstrapped companies. Valued at $1.6B+. If you’re US-based and tired of traditional banks, this is the move.

Polar is a billing platform and merchant of record. It meters usage, runs subscriptions and invoicing, and sells to your customers as the merchant of record, so sales tax is collected and remitted for you and the rest settles to your bank account. A hosted checkout and a single link are enough to start selling.

It is built for developers selling software, and especially for AI products that charge by tokens or agent runs: you send one event per model call, and Polar meters it, prices it and puts it on the invoice.

The free Starter plan charges 5% + 50c per transaction. Paid plans swap part of that for a monthly fee: Pro is $20/month at 3.8% + 40c and, by Polar’s own numbers, pays off above about $1,379 a month in sales. Organisations created before 27 May 2026 keep an Early Member rate of 4% + 40c, plus 0.5% on subscription payments.

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