Payments for Window Companies: What Stripe, Square, and the Big Processors Actually Cost You

The short version: window payments are deposits that fund factory orders — and the deposit has to cover the manufacturer's cost, not the manufacturer's cost plus a card fee you forgot to price in. A $7,000 deposit on Square's online rate costs $203 in fees; the same deposit by ACH costs $5. Nobody at Stripe or Square will ever write the window version of this page. Here's the math at your ticket sizes, with published rates checked October 2026. Also see Windows & Doors, AI for Window & Door Companies, and Tech for Window & Door Companies.

The fee table: what each processor actually charges you

Published rates, checked October 2026. Square: 2.6%+$0.15 in-person, 2.9%+$0.30 online, 3.5%+$0.15 keyed/stored. Stripe: 2.7%+$0.05 in-person, 2.9%+$0.30 online, 3.4%+$0.30 stored. Interchange-plus (typical ISO contractor pricing): ~0.3% markup over interchange.

$670 service call (reader on-site): Square $17.57 · Stripe $18.14 · Interchange-plus ~$14.74

$4,500 partial install — 6 windows (invoice link): Square $130.80 · Stripe $130.80 · Interchange-plus ~$99

$7,000 deposit on $14,000 house (online): Square $203.30 · Stripe $203.30 · Interchange-plus ~$154 · ACH (0.8%, capped at $5) $5.00

$14,000 full house, balance on install day (online): Square $406.30 · Stripe $406.30 · Interchange-plus ~$308 · ACH $5.00

$7,000 deposit (keyed in at the kitchen table): Square $245.15 · Stripe $238.30 · Interchange-plus ~$182

$406 versus $5 — same $14,000 house. At volume: 120 houses a year at $13,000 = $1.56 million. Square/Stripe online: ~$45,276/year. Interchange-plus: ~$34,320/year. Difference: ~$10,956/year — a full install crew's quarterly bonus. The rails are the same underneath every logo — Finix builds that payment infrastructure; the table is the markup on top.

The hidden row: financing. When the homeowner finances through Wisetack, GoodLeap, or Synchrony, the lender pays you — minus a dealer fee (typically 3–8% depending on the plan). That dealer fee dwarfs card processing: on $14,000, a 5% dealer fee is $700. Price the financing into the job, and never let the financing tail wag the deposit — the deposit still has to clear before the factory order goes in.

The workflow checklist the big processors fail

• Deposits sized to the factory order. The deposit must cover the manufacturer's cost after fees. A $7,000 deposit at 2.9% nets $6,797 — if the factory bill is $6,900, you're funding the job. Size deposits net of fees, or take them by ACH.
• Kitchen-table deposits without the keyed-in penalty. $7,000 keyed at signing costs $245 on Square. A mobile reader makes it $182; ACH makes it $5. The reader lives in the sales kit.
• Balance on install day. The crew finishes, the homeowner pays the balance — by text link, on the spot. The install-day glow is the best collection tool in the business; the invoice sent "tomorrow" ages 30 days.
• ACH as the default for deposits and balances. "Most of our customers pay by bank transfer and skip the fee" — said at the consult, not at install.
• Financing integration. The payment flow has to handle three paths: cash/ACH, card, and financed — with the dealer fee priced into the financed quote. Generic processors do two of the three.
• Surcharging where legal. Most states allow it with disclosure; Connecticut and Massachusetts restrict it. On $14,000 tickets the compliant surcharge is meaningful — put it in the contract.
• Card-on-file at order. Take the card when the order goes to the factory; charge the balance at install. Stored rates run higher (Stripe 3.4%+$0.30) — price it in.

Stripe's docs cover APIs. None of the big processors' pages cover the deposit-sizing problem, because that's windows.

The honest verdict on each processor

Square: fine for service calls and the install-day card swipe. Wrong for deposits and balances at flat rate — $406 on a $14,000 house is a tax, and $7,000 deposits on new accounts invite holds. Keep Square for the $670 service ticket; don't run the business on it.

Stripe: the API can do all of this — deposit flows, stored cards, financing webhooks — if you build it. Out of the box it does none of it. A developer's processor wearing a small-business costume.

Adyen: excellent interchange-plus at enterprise scale. Your 120 houses a year don't move their needle. Skip.

Chase Payment Solutions, Fiserv, Global Payments/Worldpay: quote-based, bank-led. Interchange-plus fits the ticket sizes — but you'll teach the rep what a factory order deposit is, because their training covered restaurants.

The window answer: interchange-plus merchant account underwritten for $7k+ deposits, ACH as the default for deposits and balances, financing priced into every quote, and a reader for service calls. The deposit funds the factory order — the processor shouldn't take a cut of the factory's money.

How a window company actually wires this up: notes from Finix's public docs

ClaroPro handles voice-to-invoice — the service call gets dictated at the truck and billed by text. The money movement is where Finix's public docs (docs.finix.com) get window-specific. What to look for:

• Payment links for deposit and balance. Docs cover separate collectible links per milestone — the $7,000 deposit link at signing, the balance link on install day — so the factory order and the final payment never share an awkward moment.
• Fee profiles (interchange-plus). Per-merchant pricing structures — the mechanism behind the "$406 vs $5" table above.
• ACH for deposits. Bank-transfer guides with the $5-cap math — the deposit that has to arrive whole to cover the factory bill.
• Stored cards at order time. Tokenization docs for taking the card when the order goes to the factory and charging the balance at install — with stored-card rates visible up front.
• Webhooks for order events. Payment events that fire when the deposit clears, releasing the factory order automatically — the whiteboard's job, done by software.

Architecture, not brand: deposits underwritten and sized net of fees, ACH default, install-day balance links, money events driving the factory order. That's a window payments setup.

FAQ

What does processing cost on a $14,000 window job? Square/Stripe online: ~$406 on the balance alone. Interchange-plus: ~$308. ACH: $5. Rates checked October 2026.

How big should the deposit be? Big enough to cover the factory order after processing fees — typically 50%. If the factory bill is $6,900 and you take $7,000 by card at 2.9%, you're $103 short. Size it net, or take it by ACH.

Should I offer financing? Yes — the $14,000 decision becomes a $250/month decision, and close rates show it. But price the dealer fee (3–8%) into the quote; it's the largest "processing cost" in the business.

Card or ACH for the install-day balance? Offer both, lead with ACH: "most customers pay the balance by bank transfer and skip the fee." The install-day glow closes it.

This month: size every deposit net of fees, move deposits and balances to ACH by default, put a mobile reader in every sales kit, and price the financing dealer fee into every quote. Then read Tech for Window & Door Companies — the order-tracking system is what makes the deposit math hold.