Late payment is endemic and a large share of it happens because nobody followed up rather than because the customer cannot pay.
Prevention, which does most of the work
Clear terms agreed before you start, in writing, including when payment is due and what happens if it is late.
Invoice immediately on completion. Invoices sent weeks later signal that the money does not matter to you.
Make paying easy. A payment link beats bank details, and every additional step is a reason for delay.
Deposits for anything substantial, which both improves cash flow and filters customers who were never going to pay.
The follow-up sequence
A polite reminder a few days before the due date, which frequently prevents the problem entirely.
A reminder on the due date. Another a week later, slightly firmer. A phone call after two weeks – which works far better than email and is the step most people skip.
Consistency matters more than tone. Customers pay the suppliers who chase.
When it escalates
A formal demand, stating the amount, the history, and what happens next.
Statutory interest and late payment charges, which many jurisdictions allow and few small businesses claim.
Small claims procedures, which are designed to be used without a lawyer and are cheaper than most people assume.
Debt collection, which costs a percentage and is worth it for larger amounts.
The decision to stop working
Continuing to deliver for a customer who has not paid for previous work increases the loss. Stopping is uncomfortable and it is the correct decision.