Why we built on Mercury.
Honest answer: every other US business-banking API we tested was either an aggregator (extra fees, 90-day reconnects, opaque rate limits), required a paid agreement (Plaid Business), or didn't accept foreign founders (most regional banks). Mercury was the only direct, clean, foreign-founder-friendly fit. After three years of dogfooding it on our own LLCs, we still think so.
At a glance.
Per-user cost Mercury Free SimpleFIN $1.50/mo Plaid Business Quote-based Traditional bank API Often $0, often no API
Onboarding for foreign founders Mercury Yes SimpleFIN n/a Plaid Business n/a Traditional bank API Usually rejected
Reconnect frequency Mercury Refresh tokens, indefinite SimpleFIN Quarterly Plaid Business Quarterly Traditional bank API n/a
Read-only scopes available Mercury Yes SimpleFIN Yes Plaid Business Yes Traditional bank API Varies
Move-money scope Mercury Available but we don't request it SimpleFIN n/a Plaid Business Available, paid Traditional bank API Varies
Sandbox environment Mercury Yes SimpleFIN Limited Plaid Business Yes Traditional bank API Rare
What the integration actually does.
01
Read-only OAuth, scope: read + offline_access
You authorize Mercury → Mercury issues us a token scoped only to read your accounts and transactions. We cannot move money. The token is encrypted at rest with AES-256-GCM keyed off a key we hold outside the database.
02
Daily sync, or on demand
Once a day, we fetch transactions posted since our last sync — daily is enough for year-end form preparation, and lower than aggregator-style hourly polling. Need it sooner? A "Sync now" button in the app pulls immediately. Mercury's transaction IDs are stable, so re-syncs are deduped at the database level either way.
03
Per-tenant database isolation
Your Mercury data lands in a Postgres database that holds nothing but yours. Cross-tenant queries are physically impossible by design — there's no shared "transactions" table.
04
Disconnect at any time
You revoke our access from Mercury's dashboard OR from inside Dissregarded — the token is purged, and we stop fetching. Your existing categorized data stays put. You can reconnect later without losing history.
$0
Mercury's standard plan is free — no monthly fee, no minimum balance, no per-transfer ACH fee, no outgoing USD wire fee.
Open a Mercury account →We earn a small referral fee if you open a Mercury account through this link. The fee does not change your Mercury terms or pricing. We'd recommend Mercury with or without it — they're the bank we use ourselves, and the bank Dissregarded is built on first.
Mercury-specific questions.
What if I'm a US sole proprietor, not an LLC?
Mercury has a Mercury Personal product (separate from Mercury Business) — they accept sole props, freelancers, and people who haven't formed an LLC yet. Our integration works the same way.
Does Mercury accept founders from [my country]?
Mercury has a list of currently-supported countries — they update it periodically. As of writing, they accept most countries the US has tax treaties with, but check Mercury's current list during signup. If you're rejected, you can still use Dissregarded — connect via CSV upload from whatever bank you do have.
What if Mercury sunsets the OAuth program someday?
We'd switch to SimpleFIN for everyone and stop accepting new Mercury connections. Your existing transaction history would stay; you'd reconnect through SimpleFIN. We track this risk by avoiding any Mercury-specific feature you can't get elsewhere (we read transactions, that's it).
Do you get my approval before sharing data with Mercury?
We don't share data WITH Mercury — we read data FROM Mercury, and only the accounts you authorize. Mercury never sees your Dissregarded categorization, your ledger, your tax classification, or your generated PDFs.