How to send letters and envelopes in UK and abroad at the best price.

How to Send Letters and Envelopes in UK and Abroad at the Best Price

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  1. Packlink
  2. Letters and envelopes

Send Letters and Envelopes

In this digital age, to many, sending letters by post is a bit of an enigma. You know it exists, and you may even know what to do with a letter or envelope, but do you really understand how the system works?

There are many uses for this time-honoured tradition that is still very much alive and well both in business and personal life. In this guide, we will address (pun intended) the main types of letters, their purposes, and how to send them.

The first thing to determine is that you are not sending any prohibited items. The Royal Mail has a long list of prohibited and restricted goods that you can't send by post. In most cases, they apply to parcels and packages, but there are some items that can fit in an envelope that are restricted. Visit Royal Mail's website to see the list of prohibited and restricted articles.

Choosing the Right Envelope for Your Letter

Envelopes come in all different sizes, styles, and materials. They can easily be purchased online, at your local stationery store or the post office. Your choice of envelope will depend on the letter you are sending. If you are sending a formal business letter, you wouldn't choose a funny envelope with dogs in sunglasses on it. It may seem obvious, but when in doubt, err on the side of caution.

You can purchase envelopes in any number of colours, but the standard is either white or manilla. If you are using a coloured envelope, ensure that the address on the letter is clearly visible. If you write with a black pen on a dark coloured envelope, for instance, the recipient's name and address will not show up well, making it difficult for a postal employee to see. This could result in it becoming lost. Sticking a white label on the envelope and writing the address in dark ink will solve this problem.

Here is a list and description of the different kinds of envelopes:

  • C4 envelope: This is the standard business envelope that will fit an A4 sheet of paper. The C4 is one of the most popular sizes for sending letters and documents through the post. The dimensions of a C4 envelope are 32.4cm in length, 22.9cm wide; when sending it by Royal Mail post, you will require a large letter stamp.
  • C5 envelope: This is also known as an A5 envelope. It is smaller than the C4 but still big enough to hold an A4 sheet that has been folded in half. This is one of the most common sizes of envelopes with dimensions of 22.9cm long and 16.2cm wide and requires a small letter stamp.
  • C6 envelope: This size envelope is half the size of a C4, 16.2cm in length and 11.4cm wide and will fit an A4 document or letter folded into four. This size envelope requires a small letter stamp for postage.
  • C7 envelope: This small-sized envelope is often used for invitations and cards as it only measures 11.2cm in length and 8.3cm wide. These types of envelopes require a small letter stamp for postage.
  • DL envelope: This is an envelope that measures 22 cm in length by 11cm wide, and, as with other smaller sized envelopes, these require a small letter stamp. The size is equivalent to an A4 sheet folded in three or an A5 folded in two.

There are a number of different envelope styles to choose from, depending on the look and style you want. You can get envelopes with or without a window. Window envelopes have a clear plastic panel on the front to show the address. If your envelope has a window in it, ensure that the address on the letter is clearly visible.

There is also a wide variety of self-adhesive envelopes available, which are preferable to the traditional gummed ones where you have to lick them closed yourself or use envelope glue.

The material your envelope is made out of can affect how secure it will be on its journey. Paper envelopes are generally acceptable, but if you're sending something that could be easily lost or damaged, a sturdier envelope may be a better option. It is also a good idea to use padded envelopes for sending fragile items. If you need to send a lot of documents by post, you can use a gusseted envelope. This type of envelope expands at the sides to give you extra room for your documents.

How to Address an Envelope Correctly

Before sending your letter, the__ most important step is ensuring you have the correct and full street address__ of the person you are writing to. If you are unsure of the address or missing the postcode, you can either ask the intended recipient or go online and search on Google or use a postcode finder tool.

Don't forget to check the spelling of the recipient's name and address as it will be difficult to correct it after it has been written on the envelope. Trying to remedy the situation might make it more difficult to read and result in a letter being returned or lost.

Once you have the address and the correct spelling, the next step is to actually write it on the envelope.

The address should be written on the front of the envelope, in the top-left corner. Write clearly, preferably with a ballpoint pen in black ink, ensuring it is neat and legible. The best way to write an address is in capital letters, as it avoids any confusion due to unclear writing.

Be sure to leave at least 1.5cm between your address and the stamp, as it will need to be read by the machines used for sorting your mail. Ideally, you should also leave at least 2.5cm between your address and the edges of the envelope.

How you address the envelope will depend on if it is a business letter or a personal one.

  • A personal letter should be addressed as follows

Name of the Recipient

The Street Name and House Number

Town or City



  • As an example:

Joe Bloggs

123 New Street




  • A business letter should be addressed as follows

Name of the Company


Name of the Recipient

Name of Building (If Relevant)

Street Address

Town or City


  • As an example:

ABC Company Ltd

Human Resources Department

Mr James Smith

The ABC Building

123 Old Street



If your receipt has a title before their name, for example, Lord, Baron, Doctor, Professor etc., it is polite to include it on the envelope.

Though it is not a requirement to provide a return address, it is always good practice for the sender's address to be included. On the back of the envelope, write the words return address and the actual return address underneath.

When you write an address for international mail, the format can change depending on the country's postal service. However, even if you use the same format as you do with domestic mail, it will likely get there. Just don't forget to add the country name to the address in capital letters.

As an example, if you were sending a letter to the USA when you write the address, you use a two-letter abbreviation for the state and a five-digit zip code, which serves the same purpose as a UK postcode. You can easily find a list of state abbreviations online. For instance, New York would be NY, North Carolina, NC and so on. The town, state abbreviation and zip code should all be on the same line.

  • So it would look something like this:

David Jones

912 Friendship Street

Wilmington NC 28412


Size and Weight of Your Letter

We briefly touched on the size of your letter in the section discussing the envelope's size. Your letter will either be small or large.

Small letter

A small letter has a maximum length of 24cm, a maximum width of 16.5cm and a maximum thickness of 0.5cm. It should weigh no more than 100g. With a small letter meeting these requirements, you only need a second class or first-class stamp.

Large letter

A large letter has a maximum length of 35.3cm, a maximum width of 25cm and a maximum thickness of 2.5cm. It should weigh no more than 750g. As with a small letter, if it weighs less than 100g, you can use a second class or first-class stamp. If it is more the 100g, the postage cost depends on the weight. Anything over 750g is classed as parcel post.

Royal Mail Letter Options

Exactly how much postage you will have to pay when sending mail will depend on the size and weight of your letter and if you wish to avail yourself of the Royal Mail's other services such as Signed For or Special Delivery. If you are sending a birthday card or something similar, you might want to add a little more colour to your envelope by using a decorative or commemorative stamp which you can easily obtain from your local post office.

Here are your postage options if you are using the post office as your mail carrier.

  • Second Class: This is your cheapest option for sending a letter. The Royal Mail will aim to deliver your letter in 2-3 days (excluding Sundays).
  • First Class: The Royal Mail will aim for your letter to be delivered on the following day apart from Sunday if you use a first-class stamp. However, next day delivery is not guaranteed.
  • Royal Mail Signed For: If you need peace of mind that your letter was delivered, Royal Mail offers a signed for service. This costs an additional fee and means that the recipient has to sign for the letter upon delivery as proof they received it.
  • Royal Mail Tracked: This service is similar to Signed For but also gives you a tracking number, so you can see exactly where your letter is in the postal system and when it should be delivered.
  • Royal Mail Special Delivery Guaranteed: This service offers the most security. It is special delivery which means that your letter must be delivered by 9 am (the more expensive option) or 1 pm on the next working day and needs to be signed for upon delivery. If you have valuable items being sent or time-sensitive items to be delivered, this may be the best option for you.

Alternative Options to Send Your Letter

The post office isn't the only mail carrier you can use when sending letters in the UK. There are other courier companies that will deliver your letter and parcels for you, and typically, t__his comes at an extra cost compared to__ the standard price of sending a letter via Royal Mail.

However, many of them offer extra services such as home collection, same-day delivery and tracking included, which means you can see precisely where your letter is at any given time.

With services such as that which we offer at Packlink, you can use our online tool to compare couriers at a glance, and you can be sure that your letter or package will arrive safely and on time. How it works is simple and can be completed in four easy steps online. Taking the time out to travel to your closest post office can be time-consuming and sometimes frustrating, especially if you're in a hurry. For this reason, many people are turning to online mail carriers instead.

In Summary

We hope this guide has been helpful and has answered any questions you have had about sending letters and envelopes domestically or internationally. We have also given you some helpful tips to ensure your letters arrive safely and on time.

Please be aware there are many conditions that need to be met in order for your envelope to reach the desired destination, including the size, weight and postage amount of the letter.

Although most companies today use emails almost exclusively, good old-fashioned snail mail still has its place when sending sensitive or important material that is best kept private or when messages need to get through without delay. While we will continue to use email as our primary means of communication, it's always nice to receive an old fashioned letter every once in a while.

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