Design studio owner here. Client owes $8,500 for completed website. It's been 90 days since invoice. They keep saying "check is coming" but nothing. My contract says "payment due within 30 days" but has no late fee or interest clause. What can I actually do?
Unfortunately I already deployed to their server and they have all the files. The site is live. I made that mistake early in my career and never learned...
Send a formal demand letter via certified mail. Include: amount owed, original due date, statement that you'll pursue legal action if not paid within 14 days. Something about certified mail makes people take it seriously.
Coming back to this a year later! I actually found a template online and modified it. Key elements: state the exact amount owed, reference the contract date and project name, include a firm deadline (I used 14 days), and mention that you'll pursue legal remedies if unpaid. Keep it professional, no threats or emotional language.
Quick update on my situation: I've now done 6 projects with the new contract that includes late fees (1.5% monthly) and milestone payments. Only had to enforce the late fee once, but just having it in writing makes clients take payment seriously.
Glad it landed. For the next person reading this with the same problem, the clause to add is narrower than people think.
You want the rate, the point at which it starts, and what counts as the trigger. A clause that just says late fees may apply is close to useless because it does not say how much or from when. Specificity is what makes it enforceable in practice, and it is also what makes clients actually pay on time, because a vague threat gets ignored and a specific number gets diarised.
Worth adding the timing dimension.
People sit on unpaid invoices for a very long time hoping the relationship recovers. Limitation periods are running the entire time. In California a written contract claim is four years under Code of Civil Procedure § 337(a). That is generous, but the whole point is to know the outside date rather than discover it.
Send the letter earlier than feels comfortable. The relationship is usually already over by the time you are asking strangers on a forum about it.