Royal Mail Large Letter Size Boxes

Slim cardboard boxes designed to fit within the Royal Mail Large Letter size (up to 353mm x 250mm x 25mm), so your item posts at the cheapest Large Letter rate rather than as a parcel.

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Why Large Letter boxes save money

Royal Mail prices by size as well as weight. A box that stays within the 25mm Large Letter depth qualifies for the lowest postage band, ideal for posting thin items in volume.

Why buy from Mailcoms

Mailcoms is a trusted UK mailroom supplier, trading since 2005, with fast delivery and free UK delivery over £40.

Frequently asked questions

What size is a Royal Mail Large Letter Postal Box?

The maximum dimensions you can have for a Royal Mail large letter parcel box is 35.3cm x 25cm x 2.5cm (353mm x 250mm x 25mm) with the maximum weight being 750g.

How fast is delivery?

Standard UK delivery is 3-5 working days and free on orders over £40, with a next working day option available.