If part of your business' operations is sending parcels and packages across the United Kingdom on a regular basis, then you should know that the Royal Mail has certain standards in place for shipment weight and size. There are classifications for various parcels, and this includes what comprises a simple letter to large parcels and even tubes. Being aware of the different categories imposed by the Royal Mail on different parcels can save plenty of time and effort, and even expense, as you can more easily pack and fix your parcels, so they fit the proper category. So what should you know about the different parcel categories for shipping when it comes to the Royal Mail? Let’s have a look at your special guide to shipping weight and size according to the Royal Mail.


Letters, according to the Royal Mail, should have a maximum weight of 100 grams and a maximum length of 24cm along with a maximum width of 16.5cm. In order for a letter to be categorised as a simple letter, it should also have a maximum thickness or depth of 5mm.

Large letters

For parcels to be classified as large letters, they should have a maximum weight of 750 grams along with a maximum length of 35.3 centimetres. Along with this, they should have a maximum width and depth/thickness of 25 centimetres and 2.5 centimetres, respectively.

Small parcels

A small parcel is categorised as having a maximum weight of 2 kilograms as well as a maximum length of 45 centimetres and a maximum width of 35 centimetres, along with a maximum depth or thickness of 16 centimetres.

Medium parcels

For medium parcels, classification is as follows: a maximum weight of 20 kilograms, a maximum length of 61 centimetres, a maximum width of 46 centimetres, and a maximum thickness or depth of 46 centimetres.

Large parcels

For large parcels, the Royal Mail has a different classification as well: for a parcel to be categorised as such, it would have to have a maximum weight of 30 kilograms and a maximum length of 1.5 centimetres, along with a length as well as depth or thickness of 3 metres (combined). 

For those who are sending tubes through the Royal Mail, the classification is different as well: the length of the tube along with two times its diameter should not be greater than 104 centimetres.

There are also different categories when it comes to letters and parcels according to size and weight. For example, greeting cards, postcards, bills, and personal letters are often classified as letters, whilst large letters can be made up of A4 documents, magazines, certificates, large greeting cards, and CDs or DVDs in their cases, which can also be enclosed in durable mailing boxes for maximum protection. If you are sending shoes, mobile phones, and portable speakers, these can be classified as a small parcel, and if you are sending or shipping more substantial gifts, heavier items, or bulky items, these can fall under the medium parcel category.  

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