Small Parcel Postal Boxes
£0.60 inc. VAT each
Large Letter Postal Boxes
£0.64 inc. VAT each
Medium Parcel Postal Boxes
£1.04 inc. VAT each
Royal Mail sized mailing boxes (PiP)
Cardboard postal boxes built to Royal Mail's Pricing in Proportion (PiP) size bands, so your packaging fits the cheapest possible postage tier. The range covers Large Letter, Small Parcel and Medium Parcel boxes - all UK-stocked and despatched the same working day before the daily cut-off, with VAT-exclusive pricing that falls as you buy more.
Understanding Royal Mail PiP sizes
Royal Mail prices by size as well as weight. Large Letter must be within 353 × 250 × 25mm, Small Parcel within 450 × 350 × 160mm, and Medium Parcel within 610 × 460 × 460mm. Choosing a box built to the band you post most keeps you in the lower tariff.
Match the box to your product
Use a Large Letter box for slim items through the letterbox, a Small Parcel box for typical e-commerce orders, and a Medium Parcel box for larger goods.
Why order Royal Mail sized boxes from Parcelsend UK
- Boxes engineered to Royal Mail Large Letter, Small and Medium Parcel bands
- UK-stocked, same-working-day despatch before the daily cut-off
- Trade pricing that drops as quantity rises (VAT-exclusive)
- Free UK delivery on orders over £100
- Plain stock or branded with custom print
Key takeaways
- PiP-sized boxes keep parcels in the cheapest postage tier.
- Large Letter ≤353×250×25mm, Small Parcel ≤450×350×160mm, Medium Parcel ≤610×460×460mm.
- Related ranges: postal boxes and personalised postal boxes.
Frequently Asked Questions
What is Royal Mail Pricing in Proportion (PiP)?
PiP means Royal Mail charges by the size of your item as well as its weight. Staying within a smaller size band - Large Letter, Small Parcel or Medium Parcel - keeps you in a cheaper postage tier.
What are the Royal Mail PiP size limits?
Large Letter is up to 353 × 250 × 25mm, Small Parcel up to 450 × 350 × 160mm, and Medium Parcel up to 610 × 460 × 460mm. Our boxes are built to sit within these bands.
Which box size should I choose?
Pick the smallest band your product fits: a Large Letter box for slim items, a Small Parcel box for most e-commerce orders, or a Medium Parcel box for larger goods.
Do these fit through a letterbox?
Large Letter boxes are designed to the 25mm depth limit so they're more likely to fit a standard letterbox, reducing failed deliveries. Small and Medium Parcel boxes are deeper and posted as parcels.
Can I get PiP boxes printed with my branding?
Yes. See personalised postal boxes - upload artwork online, approve a free sample, roughly 72-hour turnaround.
How quickly are they despatched?
All are UK-stocked and despatched the same working day when you order before our daily cut-off.
