You are going back through a delivered project and you see it: a price on the live site that is off by a zero, a link that points to the wrong page, a figure you miscalculated. The client signed off, paid the invoice and has not noticed. Staying quiet would be easy.
If you find your own mistake after delivering, fix it first and tell the client within a day. Here is how to size the damage, what to put in the message, who pays, and how to stop a repeat.
Tell the client within a day, because a live error keeps costing money
Report your own error within a day of finding it. A mistake you flag with the fix attached reads as competence, while the same mistake found by the client later reads as concealment, even if you meant no harm. A wrong price or a broken form keeps causing damage for as long as it stays live, so every day you wait makes the conversation larger.
The disclosure principle is the same one that applies when you are about to miss a deadline: early, short and factual beats late and long. The guide on what to tell a client when you are about to miss a deadline covers that wording. What differs here is that the error is already live and may already have cost something.
Size the damage before you write a word
Find out how long the error has been live, who has seen it and whether it has cost the client anything yet. Check the live page, analytics or order records if you can. "Live for two days, a few dozen visitors, no orders affected" is a very different message from "live for three weeks". These numbers are examples, but the habit is general: know the scale before you describe it.
If the error has already led to a real loss, such as orders placed at the wrong price, say so in your message instead of leaving the client to work it out. Hiding the impact turns a fixable mistake into a trust problem.
Fix it first, then send one message with four parts
If you have access to the live asset, correct the error before you write, so the message arrives with a solution. If you do not, tell the client right away and have the fix ready for them or their developer to apply. Then send one note covering what happened, what it affects, what you have already done, and what happens next. "I found an error in the pricing table I delivered on Tuesday: the annual plan shows ₹4,999 instead of ₹49,999. It was visible for about two days. I've corrected it and the update is live. By Friday I'll send you the check I've added so this kind of error gets caught before delivery."
Settle the money question before the client asks it
Decide your position on cost before you send the message. If the error cost you an hour to fix, the repair is part of the job and you do not bill for it. If it caused a measurable loss, check what your agreement says about responsibility and liability before you commit to anything, and offer a proportionate remedy yourself, such as free correction work, a revised deliverable at no charge, or a credit on the next invoice. If you hold professional indemnity cover, read its terms before you admit fault or offer payment.
Offering the remedy first usually resolves the matter better than waiting for the client to propose one. For larger risks, the guide on professional indemnity insurance for freelancers covers protection against claims, and the guide on writing a freelance contract that protects you shows how to define your responsibilities up front.
Treat a plain error separately from a quality complaint
An error is something factually wrong that you can point to and correct. A complaint about style or direction is a different conversation, and it needs a different response, covered in the guide on what to do when a client hates the work you delivered. Keep the two apart, because handling a plain mistake like a quality dispute turns a simple correction into an argument.
Close the gap that let the mistake through
Spend ten minutes working out how the error got through, then add one check that would have caught it. If it was a figure, verify every number against the source before sending. If it was a link, click every link on the delivered version. A single line on a checklist removes the most common repeat, and writing down the cause shows you patterns across clients.
Where to keep the record of what you changed
Keep the original deliverable, the corrected file and your message about the change together on the client's record. Rinto lets you add notes and attach files to a client's record, so you can paste in your message and attach the corrected file. If the client later asks what you delivered and what you told them, you can answer from the record instead of from memory.
Frequently Asked Questions
What should I do if I find a mistake in work I already delivered?
Fix it first if you can, then tell the client within a day. Check how long the error has been live, who has seen it and whether it has cost anything, so your message is accurate. Reporting your own error with the fix attached reads as competence, while a client discovering it later reads as concealment, even when you meant no harm. Keep a copy of the original and the corrected version, so you can show exactly what changed if anyone asks.
Should I tell the client if they haven't noticed the mistake?
Yes, especially when the error is live, public or financial. A mistake that stays hidden can surface later, when it is more expensive and harder to explain, and the delay counts against you. Even for a minor, harmless error, a short message with the fix attached builds trust at almost no cost. It shows the client that you check your own work and that they will hear about problems from you first, not by accident. That reputation is worth far more than the brief awkwardness of sending the message.
Do I have to pay for damage caused by my own mistake?
It depends on the size of the loss and on what your agreement says about responsibility and liability. A small error that cost you an hour to correct is part of doing the job, so do not bill for the repair. For a measurable loss, read your contract before replying, and consider offering a proportionate remedy yourself, such as free correction work or a credit on the next invoice. For larger risks, professional indemnity insurance exists to cover this kind of claim.
Should I fix a live site before telling the client?
If you have legitimate access and the fix is small and clearly correct, fix it first and tell the client straight afterwards, so your message arrives with the problem already solved. If you do not have access, or the change touches something the client controls, tell them right away and have the fix ready for them or their developer to apply. Either way, change nothing beyond the error itself, and note exactly what you changed so the record is clear.
How do I word a message admitting a mistake to a client?
Keep it factual and short, in four parts: what happened, what it affects, what you have already done, and what happens next. For example: "I found an error in the figure I delivered on Tuesday. I've corrected it and the update is live. Here is what changed and how I'll prevent it." Avoid long apologies and long explanations, since both make a small error look bigger and can read as defensiveness instead of ownership. Send it by the channel the client already uses for the project, so it lands where they will actually see it.