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A4 size cardboard postal box features

• Will fit through a standard UK letterbox.
• Post with confidence - meets Royal Mail's 'Large Letter' category
• Economical postage solution to help you save on postage costs.
• Simple-to-use flatpack design - just fold, tuck and pack.
• Cardboard box offers lightweight but strong postage solution.
• Perfect for books, picture frames and other flat items.
• Supplied in packs of 50 flatpack boxes.
• Quick and simple to fold into shape.
• Eco-friendly boxes that can be reused and recycled.

A4 size cardboard postal box - internal dimensions

• Internal length: 320mm (13")
• Internal width: 230mm (9")
• Internal height: 20mm (1")

A4 size cardboard postal box - external dimensions

• External length: 338mm (13")
• External width: 235mm (9")
• External height: 22mm (1")
• Pack quantity: 50 boxes

Please note: Imperial sizes provided to the nearest inch.

A4 size cardboard postal box - packing warning

This cardboard box will expand slightly beyond the stated dimensions, but please ensure it is not over-filled.

The box is designed so that its external dimensions fit Royal Mail's 'Large Letter' guidelines.

If the box is over-filled, Polybags is not responsible for any extra postal charges issued.

A4 size cardboard postal box - how to dispose

Constructed from environmentally friendly, 100% recyclable cardboard, this box is designed for hassle-free collection in regular curbside pickups or at recycling centers.

Check out our user-friendly recycling locator tool for information on recycling facilities in your local area.