Allocating to bills, not to a balance
A payment can settle one invoice, part of one, or be spread across several — which is how contractor and dealer payments actually arrive. The statement afterwards shows which bills are closed and which remain open, rather than a single balance nobody can break down. That distinction is what turns a recovery conversation from an argument about a total into a question about a specific unpaid invoice.
Every mode recorded as itself
Cash, UPI, cheque, card and bank transfer are recorded separately rather than merged into one figure. Cash is the only line that has to match something physical, so isolating it makes a shortfall obvious the same evening. Cheques can be recorded when received and marked cleared later, so a bounced cheque does not quietly sit in your figures as money you have.
The receipt itself
A numbered receipt in its own series prints on A4 or on a thermal roll and shares as a PDF on WhatsApp. It shows what was paid, by what mode, against which bills, and what balance remains — which is far more useful to the customer than a bare acknowledgement and heads off the follow-up call asking what is still due.
Advances and on-account money
Money received before a bill exists — an advance against a large order — is recorded against the party and set off when the invoice is raised, so the ledger is correct throughout rather than being corrected later. The same applies to on-account payments where the customer has not said which bills they are settling; the amount sits against the party until you allocate it.
Where payments usually go wrong
Three mistakes account for most of it. A payment recorded against the party but not allocated to any bill, so the total is right and nobody can say which invoices are open. A cash payment taken at the counter by a staff member and mentioned rather than entered, which surfaces as a shortfall that evening if you close the cash book and never at all if you do not. And a cheque counted as collected on the day it was handed over rather than the day it cleared. All three are prevented by a habit rather than a feature: record it at the moment it happens, in the same screen, before the customer leaves.