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

Your tickets are weird: $85 to show up, $450 to fix it, $1,800 for a water heater, $12,000 for a sewer line. Stripe, Square, Adyen, Chase, Fiserv, Global Payments, and Worldpay priced for coffee shops. What their published rates cost you at real plumbing ticket sizes. The $85 service call and the $12,000 sewer line run through the same phone — your payment setup has to work at both ends. Rates checked October 2026. Also see Plumbers, AI for Plumbers, and Tech for Plumbers.

The fee table: what each processor actually charges you

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 = 0.3% markup estimates.

$85 service call: Square $2.36 · Stripe $2.35 · Interchange-plus ~$1.50

$450 repair: Square $11.85 · Stripe $12.20 · Interchange-plus ~$8.90

$1,800 water heater (invoice online): Square $52.50 · Stripe $52.50 · Interchange-plus ~$38.80

$1,800 water heater (reader died, keyed in): Square $63.15 · Stripe $61.50 · Interchange-plus ~$47

$12,000 sewer line: Square keyed $420.15 · Stripe online $348.30 · Interchange-plus ~$258 · ACH (0.8%, capped at $5) $5.00

$420 versus $5 — same $12,000 job. At volume: 2,000 jobs/year at $450 = $900,000 in card revenue. Square: $23,700/year. Interchange-plus: ~$17,760/year. Difference: ~$5,940/year — a truck payment. Every processor rides on payments infrastructure — companies like Finix build the rails moving card money from your customer's bank to yours.

Two more rows your statement hides. A $250 camera inspection: Square $6.65 · Stripe $7.55 · Interchange-plus ~$5. And the costs that never appear in a rate table: the chargeback fee ($15–$25 per dispute on most processors) and the junk fees bank-led ISOs stack — statement fees ($10–$15/mo), PCI non-compliance fees, batch fees. None of them are negotiable in practice; they're avoided by picking the right provider, not by haggling.

The workflow checklist the big processors fail

Where plumbing shops actually lose money:

• Deposits. 30–50% upfront on jobs over $1,000. Stripe/Square hand you a generic "payment link" — no deposit-versus-balance tied to the estimate.
• Text-to-pay. The invoice must leave the truck as a text the customer pays from the couch.
• Card on file. Stripe 3.4% + $0.30; Square 3.5% + $0.15 — ~$10.65 on a $300 membership vs ~$7 on interchange-plus.
• The basement key-in. Reader dies, you type the card: Square jumps to 3.5% + $0.15. $63 instead of $47.
• Account freezes. Square's aggregated-risk model holds funds when your pattern breaks — a $12,000 sewer charge after a month of $150 calls is the textbook trigger.
• ACH for big tickets. $5 flat on $12,000 vs $420 keyed. Settles in 3–5 days.
• Surcharging. Legal in most states, banned in Connecticut and Massachusetts. Never lease a terminal — a $300 reader at $49/month for 48 months is a $2,352 reader.
• Financing on big tickets. Wisetack embeds in Housecall Pro, Jobber, ServiceTitan, and Workiz — invoices $500–$65,000, 0%–35.9% APR over 3–120 months, and you get paid in full when the job's done. Their own example: a $1,200 job at $400/mo for 3 months at 0% APR. The $1,800 water heater stops being a "let me think about it."
• Speed of the invoice. Send the text-to-pay link within minutes of the tech leaving — every day an invoice sits on your desk, your odds of fast payment drop. Shops that invoice same-day get paid roughly a week sooner than the Friday-batch crowd.
• Dual pricing. Show a cash price and a card price. Legal in all 50 states (unlike surcharging), no state bans to track — the card brands allow it as long as both prices are displayed. The 3% card price funds itself.

The honest verdict on each processor

• Square: fine for a one-truck side hustle at $5k/month. Outgrow it by $15k/month or your first $10,000 job.
• Stripe: great online; for plumbing it is a developer tool in a payments costume.
• Adyen: enterprise; no returned calls under ~$1M/year.
• Chase, Fiserv, Global Payments, Worldpay: quote-based, bank-led, zero plumbing guidance. Fine if you negotiate hard; miserable if you sign unread.
• Built-in field-service payments (Housecall Pro from 2.59%, Jobber 2.9% + $0.30): convenient, Square-priced. Fine for year one.
• Interchange-plus via an independent ISO: the grown-up answer past $20k/month.

If you go the bank-ISO route, get the interchange-plus quote in writing and ask about the four line items that turn a good rate into a bad deal: statement fee, PCI compliance fee, batch fee, and monthly minimum. Never sign an early-termination fee (often several hundred dollars) — and never lease the terminal; the checklist above already did that math.

ClaroPro pairs bilingual voice-to-invoice with payments — invoice and text-to-pay link leave the truck the same day.

How a plumbing shop actually wires this up: notes from Finix's public docs

Finix's public docs at docs.finix.com are the blueprint for these workflows:

Card on file — tokenization. A customer joins your annual drain plan; you never store their card number. Finix's Tokenization Forms embed a PCI-compliant form (Web, iOS, or Android SDK) in your page or app. The card number lives only inside Finix's iframe; your server gets a token starting with "TK" and creates a Payment Instrument — the stored-card object — on the customer's Identity via POST /payment_instruments. Renewals charge the stored instrument; Account Updater refreshes the card when the bank reissues it.

Deposits without a developer. Payment Links you text the homeowner — no integration — and Invoices with partial payments. Your 50% deposit on the $4,000 repipe: half now, balance later.

Authorize now, capture when done. POST /authorizations holds funds on the $1,800 estimate — reserved, not taken. Tech finishes: POST /authorizations/{id}/captures. Cancels: POST /authorizations/{id}/void. No charge-and-refund — refunds cost you the original fee on most processors.

Refunds cost you twice. POST /refunds sends the money back — and Stripe and Square don't return the original processing fee when you refund. That $1,800 water-heater refund costs you the $52.50 fee on top of returning the money. Authorize-and-capture exists precisely to avoid this.

Webhooks close the loop. Finix fires an event when the payment settles, so your dispatch software marks the invoice paid without anyone checking a bank feed — reconciliation that runs itself.

The catch: Finix is infrastructure: no-code tools work from the dashboard; API flows need a developer. Test at finix.sandbox-payments-api.com first. One more honest note: you don't open a Finix account the way you open Square. Finix powers software platforms — you get its rails through a provider built on top, the same way your truck runs on roads you didn't pave.

FAQ

Cheapest way to take a $12,000 sewer-line payment? ACH bank transfer — about $5 flat. You wait 3–5 days. Worth $400 of waiting.

Will switching processors interrupt business? Not with a one-week overlap: old account live, new charges on the new one, never cancel before the first deposit lands.

Should I offer financing on water heaters and repipes? If the ticket clears $500, yes. Wisetack (built into Housecall Pro and Jobber) shows the customer 0%–35.9% APR options and you get paid in full when the job's done. The $4,000 repipe becomes a monthly number instead of a "no."

Cash discount or surcharge? Cash discount — legal in all 50 states, no bans to track. Surcharging is banned in Connecticut and Massachusetts and capped by card-brand rules elsewhere; dual pricing (a cash price and a card price, both displayed) gets you the same math with none of the compliance.

What if a customer disputes a $12,000 sewer line? Documentation wins chargebacks: the signed estimate, before-and-after photos with GPS timestamps, the text thread where they approved the work. That's the photo-documentation layer in Tech for Plumbers — it isn't paperwork, it's dispute insurance.

The processor decision is worth roughly $6,000 a year; the workflow decision (deposits, text-to-pay, ACH on big tickets) is worth more. Move money the same day the work gets done — AI for Plumbers shows the voice-to-paid workflow. Once a year, run this fee table against your own last 12 months of statements — processors count on you never doing the arithmetic. Re-check these numbers yearly.