Business Banking Suggestions

A US operating account that pairs cleanly with Wise for US + Polish payouts

Comparison of free/low-cost US business banking options for Sponic Gardens as a newly-formed US C-corporation. Optimized for: zero monthly fees, FDIC-insured fund storage, clean handoff to Wise Business for US ACH payroll and Polish PLN payouts, basic accounting features, and a real API so the intranet can read balances and post transactions programmatically.

RECOMMENDED: MERCURY PAYOUTS: WISE BUSINESS YEAR-1 BANKING COST: $0 DRAFT: NOT FINANCIAL ADVICE

1. The shape of the answer

Prescription

Open Mercury as the primary US operating account: $0 fees, FDIC sweep coverage up to $5M, native API with sandbox, built-in basic accounting (categories, vendors, invoices, QuickBooks/Xero sync), and free ACH + domestic wires. Open Wise Business in the corporation's name as the payout rail: free to open, multi-currency balances (USD, PLN, EUR, GBP), cheap mid-market FX, and the cleanest way to pay both US contractors (via ACH or Wise) and Polish recipients (PLN local rails). Keep operating cash in Mercury; sweep what's needed for payroll to Wise weekly or per-payroll-run. If two accounts at the same provider would help isolate payroll, taxes, and operating funds, switch the primary to Relay (up to 20 free sub-accounts, similar API) — but Mercury wins the head-to-head on developer ergonomics and treasury yield. Skip Brex (now requires a $50K minimum or VC funding and pushed downmarket users to a worse tier) and skip traditional banks (Chase, BofA — monthly fees, no usable API).

2. Requirements, restated

What we need from the bank

Zero or near-zero recurring fees — no monthly maintenance, no minimum-balance penalty, free domestic ACH, low/free domestic wires.
Safe storage of funds — FDIC insurance directly or via sweep network; ideally yield on idle cash.
Clean ACH/wire to Wise — the bank funds Wise Business; Wise then handles the payout. So the bank needs cheap, reliable outbound ACH in USD and the ability to send domestic wires if Wise's ACH pull is too slow.
Basic accounting features — transaction categories, vendor tagging, invoice creation, CSV export, and QuickBooks / Xero / Wave sync. Doesn't need to be a full ledger.
Programmatic management — a real REST API (not just a CSV download) so the intranet can read balances, list transactions, push categorizations, and trigger payments. OAuth or scoped tokens, sandbox environment, documented schemas.
Acceptable to a US C-corp with one US-resident officer and one Polish-resident officer — KYC needs to accept this directly; can't require both officers to be physically in the US.

3. Why a "bank + Wise" pair, not "Wise as the bank"

Wise Business is excellent at what it does (cheap FX, local rails in 70+ countries, multi-currency balances) but is not a US bank. The USD balances are held by partner institutions and the FDIC pass-through coverage is structured but conditional. For an operating account where capital sits between SAFE close and burn, you want a real US bank with direct FDIC sweep coverage. So the pattern is:

The flow

Capital lands in Mercury — SAFE wires, customer ACH receipts, refunds.
Mercury holds the operating reserve — FDIC-insured, optionally swept to Mercury Treasury for yield.
For each payroll run, Mercury → Wise Business — a same-day ACH or wire moves only the payroll amount into Wise.
Wise pays out — USD ACH to US recipients, PLN local transfer to Polish recipients, all at mid-market FX with transparent fees.
Cards and incidentals — Mercury debit card for SaaS subscriptions and one-off vendors; Wise debit card if a payee needs a card-issued payment in PLN/EUR.

This separates "where the money lives" from "how it leaves," gives clean reconciliation, and limits Wise exposure to the amount in transit.

4. Head-to-head comparison

Provider	Monthly fee	FDIC	API	Accounting	KYC w/ Polish officer	Verdict
Mercury	$0	Sweep up to $5M	REST + OAuth, sandbox, webhooks	Categories, vendors, invoices, QBO/Xero/Wave sync	Yes — accepts non-resident officers if one US-resident principal exists	Primary pick
Relay	$0 (Pro: $30)	Up to $3M via Thread Bank sweep	REST API (Pro tier)	20 sub-accounts, deep QBO/Xero sync, Plaid native	Yes — same as Mercury	Strong alt — pick if you want envelopes
Rho	$0	Sweep up to $75M	Limited; no public REST API	Built-in spend management, AP automation, QBO sync	Yes	Good if you don't need API
Brex Business Account	$0	Sweep, but cash held in MMF	REST API (Enterprise tier required for full access)	Strong spend mgmt; bookkeeping is paid tier	Yes, but onboarding tightened — typically needs VC funding or $50K initial deposit	Skip for now
Bluevine	$0 (Std)	Direct + sweep up to $3M	No public REST API	QBO sync, basic categories	Stricter on non-resident officers	Fine fallback; no API kills it for us
Novo	$0	Direct via Middlesex Fed	Limited API (read-mostly)	Invoicing, basic reporting	US-resident officer required	Targets sole proprietors; underpowered for us
Chase Business Complete / BofA / Wells	$15–30 (waivable)	Direct	No public business-banking API	Minimal; export only	Yes (in-branch hassle)	Skip — fees, friction, no API
Wise Business (as bank)	$0 open / per-txn FX	Pass-through, conditional	REST API, very good	Light — transactions and invoicing only	Yes — best non-US-friendly KYC	Use as payout rail, not primary store

5. Deep-dive: the recommended stack

5a. Mercury (primary operating account)

What it is

Tech-startup-focused business banking, founded 2017, banking services provided by Choice Financial Group and Column N.A. (both FDIC member banks). Free to open, free to maintain, no minimum balance.

Feature	Detail
Monthly fee	$0
Minimum balance	$0
Account opening	Online, ~1–3 business days for approval
FDIC coverage	Up to $5M via sweep network (multiple partner banks)
Domestic ACH	Free, unlimited
Domestic wires	Free
International wires	$0 outgoing (mid-market FX); usually unnecessary because Wise handles this
Sub-accounts	Unlimited "vaults" with their own routing numbers
Cards	Free physical + virtual debit cards; 1% cashback on Mercury IO tier
Yield	Mercury Treasury (separate but linked) — currently ~4–5% APY on idle cash via MMF / T-bill products. Optional, not FDIC.
API	docs.mercury.com — REST, OAuth tokens, sandbox env, webhooks for transactions, payment-initiation endpoints (ACH + wire), read endpoints for accounts/transactions/cards
Accounting sync	QuickBooks Online, Xero, NetSuite, Wave (CSV); native rules engine for transaction categorization
Non-resident officer support	Accepted, provided at least one principal is US-resident with a US SSN/ITIN. Polish cofounder can be a beneficial owner / officer without issue.

Watch-outs

Mercury Treasury (the yield account) is not FDIC-insured — it's SIPC-protected because it holds money-market and T-bill funds. Keep operating reserve in the FDIC-swept checking, not the Treasury account.
Inbound international wires can land flagged for compliance review on first occurrence — open early and run a small test wire before the SAFE arrives.
Mercury closed accounts of some flagged industries in 2024 (crypto, certain international). Sponic Gardens (real-estate-adjacent hospitality / SaaS) is fine, but read the AUP before signing.

5b. Wise Business (payout rail)

What it is

Multi-currency business account from Wise (formerly TransferWise). Holds balances in 40+ currencies, provides local account details in 9+ currencies (USD ACH/wire, EUR IBAN, GBP sort code, PLN local), and converts at mid-market FX with a transparent percentage fee.

Feature	Detail
Opening fee	$31 one-time
Monthly fee	$0
USD ACH out	Free
PLN payout (Poland local rails)	Mid-market FX + ~0.4–0.6% fee on the converted amount; arrives same-day or next-day to Polish banks
EUR SEPA out	~€0.30 flat fee
Multi-currency balances	USD, EUR, GBP, PLN, and 36 more; can hold PLN reserve directly if useful
Batch payments	CSV upload up to 1,000 recipients per batch — ideal for payroll runs
API	docs.wise.com — full REST API, sandbox, OAuth, payment initiation, quote/transfer/recipient endpoints
FDIC	USD balances held with partner banks; pass-through coverage exists but is structurally different from a direct bank account — not for primary fund storage
Accounting sync	QuickBooks, Xero, Wave; native transaction CSV with FX details

Why Wise specifically for Polish payouts

Wise routes PLN transfers via Polish local rails (Elixir / BlueCash), not via SWIFT. Recipients get the same-day PLN payment with no intermediary-bank fees deducted, at near-mid-market FX. The alternative — wiring USD to a Polish bank and letting them convert — typically costs 2–4% in spread plus $15–40 in correspondent fees per transfer. On a $5K PLN payroll, Wise saves ~$100–200 per run versus a traditional USD wire.

6. Programmatic management — what the API gets us

Mercury's API is the reason it wins. The intranet at in.sponicgardens.com can:

Read live balances + transactions for a runway widget on the founders' dashboard — pull from Mercury hourly, cache in Supabase, display in the existing dashboard layout.
Auto-categorize transactions using LLM classification keyed off vendor name + amount, then push the category back to Mercury via the API so QuickBooks gets the right code at sync time.
Trigger payments from inside the intranet — payroll, contractor invoices, vendor bills. Two-officer approval flow lives in the intranet; Mercury executes after the second signature.
Webhook on every transaction → land in a Supabase table → trigger Slack/Telegram notification, anomaly detection, weekly cash-summary email.
Sync to Wise via API for the payroll step: intranet schedules the Mercury → Wise transfer + the Wise → recipients batch in one click.

Concrete first integration

Smallest useful slice once Mercury is open: nightly cron pulls all transactions from Mercury's API into a finance.transactions table in Supabase, an edge function classifies new ones with an LLM, and a single page in the intranet (/en/finance/runway) shows current balance, 30-day burn, and runway in months. Mercury API is similar in shape to the Spotify and Sonos integrations already wired up here.

7. Polish-side accounts — does the Polish sole proprietor need any?

Per the corporate structure plan, the Polish cofounder operates as a Polish sole proprietorship (JDG) and invoices the US C-corp under a services agreement. Her business banking is separate from the company's. She needs her own Polish business account (mBank, ING Bank Śląski, Santander, or Revolut Business are all fine) to receive Wise transfers and pay her ZUS / taxes. That's her cost, not the company's.

The US C-corp does not need a Polish bank account, a PLN-holding account, or any Polish banking presence. Wise's PLN payout rail handles the cross-border flow; everything the company does sits in US-domiciled accounts.

8. Accounting integration plan

Year 1 — minimum viable

Mercury sub-accounts: Operating, Taxes (set aside 21% federal corp tax + state), Payroll Float, SAFE Proceeds.
Wave Accounting (free) as the GL; Mercury → Wave sync via CSV or QuickBooks-format export.
Manual monthly close: 30 minutes, mostly categorizing the ~30–60 transactions/month.
Year-end: hand the GL to the solo CPA preparing Form 1120 (per corp plan).

Year 2 — once transaction volume justifies it

Upgrade to QuickBooks Online ($30/mo) with Mercury direct sync — auto-pulls transactions and matches receipts.
Use the Mercury API to auto-attach the matching Wise transaction memo to each Mercury outbound, so payroll lines reconcile without manual touch.
Add Ramp or Rippling for spend management if expense volume scales; both have free tiers and good APIs.

9. Practical setup sequence

Form the Texas C-corp and get the EIN (per corp plan).
Apply to Mercury as soon as the EIN is in hand. Have ready: Certificate of Formation, EIN letter, US-resident officer's SSN + ID, beneficial-ownership details for both cofounders. Approval typically 1–3 business days.
Apply to Wise Business the same day. Wise's KYC is independent. Lower volume during setup so use a smaller initial transfer to verify the rail.
Move the initial SAFE / founder contribution into Mercury. Wire test of $100 from a personal account first to confirm the rail.
Create Mercury sub-accounts for Operating, Taxes, Payroll Float.
Issue Mercury API token (Settings → API tokens). Store in Bitwarden under DevOps-sponicgarden as Mercury API Token.
Run a first payroll dry-run: Mercury → Wise transfer of $10, Wise payout of $10 USD to one US recipient and PLN equivalent to one Polish recipient. Confirm timing and confirm the recipient's bank treats the inbound correctly.
Wire the intranet: read-only Mercury integration first (transactions + balances); payment-initiation later behind a two-officer approval flow.

10. Trade-offs explicitly summarized

Mercury over Relay as primary

Gives up: Relay's stronger "envelope budgeting" UX with up to 20 named sub-accounts; slightly better native Plaid integration.

Gains: Better-documented API, more startup-tooling integrations (QuickBooks Online, Xero, NetSuite), Mercury Treasury for yield, larger FDIC sweep ($5M vs $3M), better KYC flexibility for non-resident officers.

Mercury + Wise versus Wise alone

Gives up: Single-provider simplicity. Two sets of credentials, two API tokens, two reconciliation processes.

Gains: Direct FDIC sweep on operating reserve (Wise's USD coverage is structurally weaker); separation of "store" from "transfer," limiting in-transit exposure; access to Mercury Treasury yield (~4–5% APY) on idle balances; Mercury's API and sub-account model are stronger for programmatic intranet integration.

Free tier on Mercury / Wise versus paid plans

Gives up: Higher API rate limits, dedicated support, some advanced expense-management features.

Gains: $0/mo recurring. Free tiers are sufficient through at least 200 transactions/month; revisit only when API rate-limited or support-blocked.

Skipping Brex

Gives up: Best-in-class corporate card with high credit limits, strong rewards on SaaS spend, integrated travel booking.

Gains: Avoidance of the $50K initial-deposit floor that Brex now requires for non-funded startups, and avoidance of the worse-tier "Brex Essentials" they sometimes push pre-funded teams toward. Revisit Brex post-SAFE if the card economics matter.

11. Open questions / next actions

Confirm trust authority for Mercury KYC. Mercury's KYC asks for beneficial owners ≥ 25%. If the trust is a ≥25% holder via the SAFE conversion, Mercury will want trust documents and trustee ID. Confirm with the trustee before SAFE close.
Decide on a Mercury Treasury allocation policy. Default proposal: keep one quarter of burn ($X) in FDIC checking; sweep the rest to Treasury for yield. Set policy before first SAFE arrives.
Run the test payroll (step 7 above) before the first real payroll cycle — never debug an FX rail under pressure.
Add the Mercury read-only integration to the intranet as the first concrete dev task once accounts are open. Skeleton: finance.transactions table, nightly pull, /en/finance/runway page. Spec it as a devtask under devtasks.
Decide where to store API tokens. Recommend Bitwarden collection DevOps-sponicgarden with one item per provider (Mercury, Wise), surfaced to edge functions via Supabase secrets per Agent DevOps SOP.