Proof of Postage Explained: What It Is and When You Need It (UK)

"Proof of postage" is one of the most misunderstood terms in UK posting. People often assume it proves a letter arrived - it doesn't. Here's exactly what it does prove, how to get it, and when you need something stronger.

What proof of postage actually proves

A proof of postage (Royal Mail calls the paper version a Certificate of Posting) is a receipt confirming that you handed a specific item to Royal Mail on a specific date. That's all it proves: the date you posted something. It says nothing about whether the item was delivered, when it arrived, or whether the recipient ever saw it.

This distinction matters most when a deadline is involved. If you need to show you sent a document "by" a certain date - a tax return, a legal response, a tenancy notice - proof of postage is often exactly the evidence required, because many deadlines are defined by the date of posting, not the date of receipt.

How to get proof of postage at a Post Office

Ask for a Certificate of Posting at the counter when you hand over your item - it's free for standard mail. You'll usually need to fill in a small form (or the clerk will do it for you) with a brief description of the item and the recipient's address, and the clerk stamps and dates it. Keep this certificate safe; Royal Mail does not keep a copy for you.

Proof of postage vs tracking vs Signed For

• Proof of postage: proves when you sent it. Free. No information about delivery.
• Tracked (24/48): proves transit progress and, in most cases, that it reached a "delivered" or "safe place" status - but doesn't require a signature.
• Signed For: adds a named signature requirement on delivery, giving you a specific person's confirmation of receipt.
• Special Delivery: combines guaranteed delivery timing, full tracking, a signature and built-in compensation - the strongest evidence available.

If you need to show when something was posted, keep your posting evidence and check the recipient's rules. For a signature-based service, compare Royal Mail Signed For with Special Delivery. Neither a posting certificate nor a delivery signature proves the contents or automatically establishes valid legal service.

When online letter services include proof of postage automatically

Many online print-and-post services, including Send Letters Online, include a proof of postage certificate with every order automatically - showing the date the letter was handed to Royal Mail, without needing to visit a Post Office counter to ask for one.

What to do if a letter is disputed as "never sent"

If a recipient claims they never received something and the timing matters, your proof of postage (or order confirmation from an online service) is the first piece of evidence to produce. For anything high-stakes, pairing it with a tracked or Signed For service closes the gap that proof of postage alone leaves open - proof that the item was actually delivered, not just handed over.