Almost every receipt template on the internet is a re-skinned invoice. The fields are the same, the totals block is the same, and the only difference is a stamp. That is the wrong document. An invoice is a demand for payment — it looks forward to money that has not arrived. A receipt is evidence that payment happened, and evidence has a different shape: it has to say how much was tendered, by what means, on what date, and what was still owed when the customer walked away. None of those four things appear on an invoice, which is why a stamped invoice is a poor receipt no matter how it is styled.
The arithmetic is where the difference becomes concrete. A bill total is one number. A tender reconciliation is at least five: what was due, what was handed over, what change went back, what was applied, and what remains. This builder records each tender separately — a deposit by check in March and the final by card in April are two rows with two dates, not one blurred figure — and it sums them in whole cents rather than in floating-point dollars. That is not pedantry. Add 20.10, 5.20 and 74.70 in double-precision arithmetic and you get 99.99999999999999, so a $100.00 bill paid in three parts leaves fourteen zeroes and a one still outstanding, and a receipt built the naive way prints "partial payment received, $0.00 remaining". Money is counted in cents here for exactly that reason.
Plumbing runs on progress payments — a repipe or a sewer replacement gets paid in two or three bites, often across weeks. That is exactly where split-tender arithmetic matters: a deposit by check, a final by card, and the two have to total the bill to the cent. This builder sums tenders in whole cents, so three payments that should make the total exactly whole do, instead of leaving a fraction of a cent that reads as an unpaid balance.
The other thing a receipt has to survive is being handed to an accountant. Your customer may be keeping it for a business deduction, a warranty claim, or a rental-property expense, and the rules on what makes a slip of paper adequate are published. Under 26 CFR 1.274-5(c)(2)(iii), documentary evidence is adequate to support an expenditure if it contains enough information to establish the amount, the date, the place, and the essential character of the expenditure — and the same regulation is where the widely-repeated $75 figure comes from, though it belongs to the section 274(d) travel and listed-property rules rather than to ordinary business expenses, which fall under 26 CFR 1.6001-1(a) and carry no published dollar floor at all. The element people leave off is "essential character". "Service call — $340" establishes an amount and nothing else. "Replaced 50-gallon gas water heater, new T&P valve and expansion tank" establishes what the money bought, which is what decides whether the cost reads as a repair or an improvement. This builder lists the elements, flags the missing ones worst first, and tells you what each one is for.
The card fee is the most-litigated line on a trade receipt, and it is the one where honest templates are rarest. There is no national rule. 15 U.S.C. 1602(r) defines a surcharge as any means of increasing the regular price to a cardholder that is not imposed on customers paying by cash or check — an increase above the posted price. A cash discount runs the other way: 15 U.S.C. 1666f stops a card issuer from preventing a seller offering a discount to induce cash payment, and that discount is not a finance charge so long as it is offered to every buyer and disclosed clearly. Those are two different mechanisms, not two labels for one practice, and the test is the posted regular price. On top of that sit two layers of rules. The networks cap the fee at your own cost of acceptance — Visa at the lesser of your merchant discount rate or 3 percent, Mastercard at the lesser of your average effective rate or 4 percent — and both require the dollar amount on the receipt itself plus signage at the point of sale. Then the states: Connecticut bars a surcharge on any method of payment outright, Massachusetts bars it on credit cards, Colorado allows it up to 2 percent and requires it as a separate line item on the customer's receipt, New York allows it but dictates that the credit-card-inclusive total be the posted price. This builder asks which state you took the payment in and scores against the statutes we read. For every other state it prints "not evaluated for your state" — because a template that guessed would be worse than one that admitted the gap.
The last few fields are the ones that make the receipt useful a year later. An invoice reference, so the receipt ties back to the bill it settles rather than floating free — the first thing anyone asks for when a partial payment is disputed. A warranty and return-terms line, because a warranty claim is made against a receipt and a return policy that lives only on a wall sign is unenforceable in practice. And the retention period, printed on the export: the IRS publishes 3 years from the filing date as the general rule for supporting documents, with 6 years where unreported income exceeds a quarter of gross income, 7 for a bad-debt claim, and 4 for employment tax records. A plumbing receipt for plumbing work is worth keeping that long, and telling the customer so costs you a line.