Short answer: to send a letter in the UK, put it in an envelope, write the recipient's name and address in the centre with the postcode on its own line, add your return address on the back, stick a First or Second Class stamp in the top right-hand corner, and post it in a Royal Mail postbox or at a Post Office. No printer or stamps? You can also send a letter online and have it printed and posted for you.
How to send a letter, step by step
- Write or print your letter. Sign it if it needs a signature.
- Choose an envelope that fits. A letter folded into a standard envelope (up to 24 × 16.5 cm and 5 mm thick) goes at the normal letter rate. Anything bigger, such as an A4 sheet sent flat, is a Large Letter and needs a Large Letter stamp.
- Address the envelope (see the format below).
- Add your return address on the back of the envelope, so the letter can come back to you if it can't be delivered.
- Add the right stamp in the top right-hand corner: First Class for speed, Second Class to save money, and a Large Letter stamp if the envelope is over letter size or 100 g.
- Post it in any Royal Mail postbox before the collection time shown on the box, or hand it in at a Post Office counter if you need proof of postage or a signature.
How to address a letter in the UK
Write each part on its own line, aligned left, in the centre of the envelope:
- Recipient's name (and company, if it's a business)
- House number and street name
- Locality, if needed
- Town or city
- Postcode, on its own line
Write the town in capitals if you can, and always include the postcode: it is what sorting machines read first.
Which stamp do you need?
- First Class: Royal Mail aims to deliver the next working day (Monday to Saturday).
- Second Class: cheaper, and aims to arrive within three working days. Second Class letters are now delivered on alternate weekdays, so allow a little longer.
- Large Letter stamps: needed when the envelope is bigger than 24 × 16.5 cm, thicker than 5 mm or heavier than 100 g (up to 35.3 × 25 cm, 2.5 cm and 750 g).
Stamp prices change every year, so check Royal Mail's current prices before you buy. If you post a letter with too little postage, Royal Mail may ask the recipient to pay the difference plus a fee before they can collect it.
| Size | Max dimensions | Max thickness | Max weight |
|---|---|---|---|
| Letter | 24 × 16.5 cm | 5 mm | 100 g |
| Large Letter | 35.3 × 25 cm | 2.5 cm | 750 g |
When you need proof it arrived
For important post (a notice to quit, a complaint, a letter before action or anything with a deadline), use a service that records delivery:
- Signed For: the recipient signs on delivery.
- Special Delivery Guaranteed: next working day by 1pm, tracked, with compensation if it's late.
- Tracked services: you can follow the letter online until it is delivered.
Keep your proof of postage. Our guide to the cheapest way to send a tracked letter compares the options.
How to send a letter without a printer or stamps
You don't need a printer, envelopes or a trip to the Post Office. With printle you can:
- Write your letter online, or start from a formal letter template, or
- Upload a PDF or Word file you have already written.
We print it, pack it flat in a hardbacked envelope (never folded), and send it tracked to any UK address. Orders placed before 2pm on a working day are dispatched the same day. A one-page tracked letter costs £4.27, delivered.
Should a letter be folded or sent flat?
Folding an A4 letter into thirds lets it travel at the cheaper letter rate. Sending it flat keeps it crease-free, which matters for documents that will be scanned, filed or signed. A flat A4 sheet is a Large Letter. That is why every printle letter goes flat in a hardbacked envelope, tracked.
Sending a letter to a prisoner or your MP
- Send a letter to a prisoner: prisons have their own rules on what can be enclosed and how to address the envelope.
- Write to your MP: find your MP and send a printed letter to their constituency or Westminster office.
FAQs
Do I need a stamp to send a letter in the UK?
Yes. Every letter needs postage, either a stamp or a printed postage label. If it is underpaid, the recipient may be asked to pay the difference plus a fee. Online letter services include the postage in the price.
Where do I put the return address?
On the back of the envelope, so it isn't mistaken for the delivery address.
How long does a First Class letter take?
Royal Mail aims to deliver First Class the next working day. Second Class aims to arrive within three working days.
Can I send a letter online in the UK?
Yes. Upload your document or type it online, add the address, and a service like printle prints and posts it for you, tracked.
How do I send a letter to a company?
Address it to the company name (and a person or department if you know one) at its postal address. For anything important, use a tracked or signed-for service and keep proof of postage.
Send your letter online: printed, sent flat and tracked from £4.27. Write a letter · Upload and send