Royal Mail Large Letter Size Boxes

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We have a lot of customers asking us what boxes we sell that are within the Post Office’s regulations on Large Letter sizes. So, we’ve made a list!

What are the Royal Mail Large Letter Size Dimensions?

A large letter sized box can be no larger than 353 x 250 x 25mm, and weigh no more than 750 grammes.

Please note, due to the manufacturing process, there may be a very slight variation of size. It is strongly suggested you order a sample and check it yourself.

Royal Mail Large Letter Size Compatible Boxes

These boxes fit within the permitted size as allowed by Royal Mail.

We can also make boxes to your requirements! Our custom made packaging and printing section has everything you need.

Other Postal Supplies

Bubble Bags, Padded Envelopes, Jiffy Bags and Mailers

Parcel paper, bubble wrap and corrugated cardboard rolls

Tapes & Dispensers, Envelopes, Postal Tubes, Luggage Tags, Shredded Polypropylene, Wood Wool and Loose Fill