If you run an e-commerce store or resell items on platforms like Vinted, eBay, Depop, or Etsy, choosing the right parcel carrier directly impacts your margins. For lightweight items and apparel, Royal Mail and Evri (formerly Hermes) are the two dominant UK couriers.
While both offer competitive pricing and nationwide drop-off options, their size thresholds, weight brackets, and packaging restrictions differ significantly. Sending an item via the wrong carrier or in an oversized bag can quickly eat into your profits.
In this guide, we compare Evri and Royal Mail side-by-side to help you choose the most cost-effective service and packaging for every order.
Size & Weight Comparison: The 25mm Rule vs. Volumetric Freedom
The fundamental difference between Royal Mail and Evri comes down to how they define a “small” shipment: dimensions versus weight.
| Royal Mail Large Letter | Evri Postable |
|---|---|
| Max: 353 x 250 x 25mm Weight: Up to 750g Focus: Strict 25mm thickness | Max: 350 x 230 x 30mm Weight: Up to 1kg Focus: 30mm thickness allowance |
1. Royal Mail Large Letter
- Max Dimensions: 353 x 250 x 25 mm
- Max Weight: 750g
- Best For: Very flat, lightweight goods like single t-shirts, phone cases, jewellery, and documents.
- The Verdict: Unbeatable value if your item stays under 25mm thick and under 250g.
2. Evri Postable
- Max Dimensions: 350 x 230 x 30 mm
- Max Weight: 1kg
- Best For: Bulky t-shirts, light jumpers, or jeans that exceed 25mm thickness but weigh under 1kg.
- The Verdict: Highly forgiving for apparel sellers because of the extra 5mm thickness allowance and higher weight limit.
Shipping Cost & Size Matrix (2026 Comparison)
| Parcel Tier / Weight | Best Bag Size | Royal Mail Option | Evri Option | Cheaper Winner |
| Flat Garment (<250g, <25mm) | 9″ x 12″ (229x305mm) | Large Letter (2nd Class) | Postable | Royal Mail |
| Bulky Garment (<1kg, 25–30mm) | 9″ x 12″ (229x305mm) | Small Parcel Tier | Postable | Evri |
| Medium Goods (1kg – 2kg) | 12″ x 16″ (305x406mm) | Small Parcel | Standard Parcel | Evri |
| Heavy / Multi-item Bundles (>2kg) | 14″ x 19″ (355x483mm) | Medium Parcel | Standard Parcel (Up to 15kg) | Evri |
Best Poly Mailer Sizes for Each Courier
Choosing the right grey mailing bag prevents excess fabric flap, reduces dimensional bulk, and ensures easy labeling.
- For Royal Mail Large Letter:
- Recommended Bag:
Grey Mailing Bags | 9" x 12" (225x300mm) | Royal Mail Large Letter A4 Size - Why: Fits precisely inside the 353 x 250 x 25 mm footprint without folding over excess material.
- Recommended Bag:
- For Evri Postable & Standard Parcels:
- Recommended Bag:
10" x 14" (250x350mm)or12" x 16" (300x400mm) - Why: Perfect for jeans, hoodies, and shoes. Evri thermal labels 4×6″ fit easily on the smooth poly surface without creasing over the edges.
- Recommended Bag:
3 Packaging Tips to Cut Shipping Costs
- Use Thermal Labels for Evri ParcelShop Drop-Offs: Applying standard 4″x6″ direct thermal labels directly to self-seal poly mailers guarantees scannability at Evri ParcelShop terminals and Royal Mail Customer Service Points.
- Compress Garments with Self-Seal Bags: Always push out trapped air before flattening the self-seal lip down. Compressing a folded jumper can reduce its depth from 32mm down to 24mm, saving you from a Small Parcel charge.
- Keep Heavy-Duty Tape Handy: If packing heavier or sharp-cornered items for Evri standard parcels, reinforce poly mailer seams with strong solvent packing tape to prevent tears during automated hub sorting.
