Postage Formats

Below is a breakdown of postage formats and their allowed specifications according to Royal Mail guidelines.

Letter

Including most letters, bills, statements and some brochures or catalogues.

• minimum size: 100mm x 70mm
• max size: 165mm x 240mm (oversized C5)
• max thickness: 5mm
• max weight: 100g
• other criteria: must be uniform thickness across the surface.

Large Letter

Including A4 envelopes, most brochures and catalogues.

• max size: 353mm x 250mm
• max thickness: 25mm
• max weight: 750g
• other criteria: must be uniform thickness across the surface.

A3 Packet

Including A3 brochures and magazines and other oversized direct mail items.

• max size: 420mm x 297mm
• max thickness: 25mm
• max weight: 750g

Packet

Larger mailing item when any one of the dimensions exceeds A3 Packet.