A card payment automatically leaves a trail — a bank statement line, a processor record, a timestamp neither side can really dispute. Cash leaves nothing unless someone deliberately creates a record of it, which is exactly why skipping a receipt matters more for cash than for card.
No automatic record means the receipt IS the record
For a card transaction, a lost receipt is an inconvenience — the bank statement still proves the payment happened. For cash, if no receipt was issued, there's genuinely no third-party proof the transaction occurred at all.
This matters for both sides
A customer without a cash receipt has no proof of purchase for a return or warranty claim. A business without a record of the cash it took in has a harder time reconciling daily totals and can run into real bookkeeping and tax problems down the line.
It also protects against disputes
"I paid you $50" versus "you paid me $30" is an unresolvable argument without a receipt. A simple printed or handwritten record with an amount, date, and what it was for settles the question before it becomes one.
Make issuing one the default, not the exception
Some businesses only write a receipt when asked, which means most cash transactions go unrecorded. Making it standard practice for every cash sale, however small, closes this gap without adding much time to each transaction.