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How to post a letter

These days, people usually send letters because they’re important. Make sure you’ve got it right

Whatever the reason you’re sending a letter – whether it’s an important document or a heartfelt message to someone special – we know it’s important that it arrives on time. Here’s how to make sure of that

Step 1: Check you can post

Some items are prohibited

A few items that you might not think twice about are prohibited from being sent by post, including lottery tickets. Read the full list of restricted and prohibited items so that you can be sure you’re posting legally and safely.

Step 2: Choose an envelope

When mailing a letter, postage cost depends on the size and shape of the mail piece.
There are envelopes available for a variety of important documents as well as foldable letters. You can get any of them in your local branch.

Step 3: Address your mail

Think of it as ordering the info smallest to largest, followed by postcode. So the addressee goes first, then their house name/number and street name, locality (if necessary), town/city, county (if necessary) and postcode. Align all to the left.
Getting your delivery address right is crucial. If you're not sure of the address you're sending to – whether an entire address or just part of one – use a digital maps service or search engine like Google or Apple Maps to fill out the remaining details.

You can find more advice in our guide on how to address mail.

Step 4: Weigh your letter

The size and weight of a letter will also determine the type of postage you’ll need to attach.
Weighing your letter before you get to a branch can help you buy the right postage and spend just what you need to. You can do it at home with scales for an accurate reading or approximate to be sure it’s within a specific range. Remember that the weight of your item will determine the kind of postage you’ll need.

Step 5: Choose a postage option

Choose your postage depending on how soon you want your letter to arrive and whether you need it to be tracked and signed for.
The size of your letter and speed and security you need to send it with will determine what kind of postage you’ll need, and what price you’ll pay. There are two different sizes of letter which are called “letter” and “large letter”.

  • Letters have a max width of 16.5 centimetres, a max length of 24cm and a max depth of 0.5cm
  • Large letters have a max width of 25cm, a max length of 35.3cm and a max depth of 2.5cm. Weight also becomes more important with large letters

You can send letters by 1st class or 2nd class post. Letters sent 1st class are usually delivered in one working day and those sent 2nd class within 3 days, but neither are guaranteed.

We also provide postage options for items you need to guarantee to arrive before a specific time. Called Special Delivery Guaranteed by 9am® and Special Delivery Guaranteed by 1pm®, these guarantee delivery by 9am and 1pm the next working day respectively.

Use our postage price finder to find a preferred method and price for sending your letter.

Step 6: Place your stamp/postage sticker on your envelope

The days of licking stamps are over. Just peel your stamp and stick it in the top right-hand corner of your letter.
You’ll need your stamp to be clearly visible, not bent over an edge and on the same face of your parcel as the address. Many stamps contain barcodes to assist in tracking, so it’s important that the stamp is flat and easy to scan.

Step 7: Post your letter

If you’ve got the right stamp and your address is correct, you can head over to your nearest post box.
Or pop in to see us at your local branch. We’re on hand to help with any of your queries, help you find the right postage and get your package on its way.


Here’s an example of how to address and stamp your post. You’ll see that the address is on the left-hand side of the item while the stamp is in the top right-hand corner

We know that sometimes, especially if you’re reusing packaging, this isn’t always 100% possible. But get as close as you can and make sure that the address is clearly legible and the stamp clearly visible

How to address mail

Send parcels from a local Post Office

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Common posting questions

  • The cost of sending a large letter will depend on how much it weighs. The maximum it can weigh is 750g, and it needs to be able to fit through the letterbox assistant in your local Post Office. The price will also depend on what kind of tracking and delivery time guarantees you want to purchase.

    Decide what kind of postage you want – how quickly you need it to arrive and if you want it tracked or guaranteed – and use our price finder to get an idea of the cost.

  • You can buy stamps over the counter in all Post Office branches. You can also buy the stamps you need from our self-service kiosks in selected branches. Simply choose the type you want and the amount, and the machine will print them for you.

  • There are a few fast-track services on offer. The fastest is Special Delivery Guaranteed by 9am® which, as the name suggests, guarantees delivery by 9am the next day. Next is Special Delivery Guaranteed by 1pm®, which offers the same service but with a slighter later delivery time the next day.

    Then there are the signed-for services, which have 1st class and 2nd class options. These are comparable to normal 1st and 2nd class services with the added advantage of getting a recipient signature when delivered, so you know your item has arrived.

    1st class service usually arrives within two working days and 2nd class usually within three.

  • To find out the current prices for 1st and 2nd class stamps for letters and large letters check our pricing guide.

Need some help?

Posting help and support

Find answers to common questions about posting services:

Visit our posting support page