Letterbox Boxes vs Postal Boxes: What Is the Difference?
Letterbox vs postal boxes: which format suits your products and shipping budget best.
Key differences
Quick answer
Letterbox boxes are thin (under 25mm) and fit through the door for large letter postage rates. Postal boxes are deeper and ship as parcels. Use letterbox boxes for thin, light items like jewellery, cosmetics, and phone cases to save £2-3 per shipment. Use postal boxes for thicker, heavier, or fragile items that need more protection. Many businesses use both formats for different products.
Cost comparison
Large letter from 93p vs small parcel from £3.35. The postage saving dwarfs any box cost difference.
They use less material due to their thinner construction.
Items fit through the door, eliminating redelivery costs.
Protection comparison
Postal boxes provide superior protection through thicker walls and more internal space for cushioning. Letterbox boxes offer adequate protection for flat, robust items but are not suitable for fragile three-dimensional products. The 25mm thickness limit means minimal cushioning space.
Sizing guidance: letterbox sizing or products that fit letterbox.
When to use each
Letterbox and postal boxes
Both formats available from ProcuraPack in stock and custom sizes.
Browse letterbox boxesFrequently asked questions
Letterbox boxes are under 25mm thick and fit through letterboxes for large letter rates. Postal boxes are deeper and ship as parcels.
Letterbox boxes qualify for large letter rates (from 93p) vs small parcel (from £3.35).
Yes, many businesses use letterbox boxes for thin items and postal boxes for thicker products.
For flat, robust items yes. Not suitable for fragile 3D items needing significant cushioning.
Items under 25mm thick: jewellery, phone cases, cosmetics, thin books, stationery, seeds.
Part of our guide
Product Guide: Letterbox Boxes
Expert guides on letterbox packaging, from sizing and Royal Mail rules to branding and sustainability.
Browse all guides →
