Check facts before chasing payment
Confirm the invoice reached the right contact, matches an accepted scope and includes the details accounts payable needs. A missing purchase order or tax field can delay processing even when the customer intends to pay.
Check your bank records and any partial payments before sending a reminder. Avoid repeating a demand for an amount that was already settled.
Use a courteous escalation sequence
A few days before the due date, send a friendly reminder when appropriate. After the deadline, reference the invoice number, amount, due date and a direct way to resolve questions. If the delay continues, consult the written agreement before suspending work or escalating.
Document your communications and keep the original invoice and contractual terms. Offer a realistic payment schedule only if it works for your business.
Understand the limits of late charges
Interest and penalties vary by contract and local law. Do not add a fee simply because a calculator gives you a number; check whether the fee was disclosed and permitted.
The late-payment calculator offers flat and simple-interest illustrations using your own inputs. It does not determine enforceability or issue a demand notice.