Royal Mail and Courier Requirements for Bubble Mailers
Royal Mail and courier rules for bubble mailers: sizes, weights, and rates.
Royal Mail rules
Quick answer
Small bubble mailers with thin items can qualify for large letter rates, saving over £2 per item. The 25mm thickness limit is critical: bubble lining takes 10-15mm, leaving only 10-15mm for contents. Sizes A and B with thin items often qualify. Larger sizes or thicker items ship as small parcels. Always measure packed, sealed mailers to confirm classification.
Courier rules
Most UK couriers classify by weight and dimensions. Bubble mailers are lighter than boxes, often resulting in cheaper rates. Some offer specific mailer rates.
Costs: shipping costs or sizing.
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Browse bubble mailersFrequently asked questions
Small sizes with thin items can if total thickness is under 25mm.
353x250x25mm, 750g.
10-15mm for the lining alone.
Always. Contents add to the thickness.
Sometimes. Compare rates for your dimensions and weight.
Part of our guide
Product Guide: Bubble Mailers
Expert guides on bubble mailers and cushioned shipping envelopes for safe, efficient deliveries.
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