For Shopify merchants, packaging decisions directly impact shipping costs, delivery speed, and customer experience. When using Royal Mail, packaging plays an even bigger role because pricing is heavily influenced by parcel size categories and weight thresholds.
Choosing between custom packaging and Royal Mail carrier box sizes can determine whether you stay within a cheaper pricing tier or accidentally move into a more expensive one.
In this guide, we’ll break down how to use both packaging types effectively inside Shopify and when each option makes the most sense.
In This Article:
- Royal Mail Packaging Options for Shopify Sellers
- Custom Boxes in Shopify With Royal Mail Shipping
- Custom Boxes vs Royal Mail Carrier Boxes in Shopify: Comparison
- When to Use Royal Mail Carrier Boxes vs Custom Boxes
- How to Enable Custom and Carrier Boxes in Shopify
- Royal Mail Packaging Scenarios: Real Shopify Examples
- Conclusion
- FAQ’s
Royal Mail Packaging Options for Shopify Sellers
Royal Mail doesn’t offer “free boxes” like some carriers. Instead, it uses strict size-based categories that define pricing.
The most commonly used Royal Mail packaging categories include:
Royal Mail Standard Sizes
- Royal Mail Letter
Max weight: 100g
Very thin items like documents - Royal Mail Large Letter
Max weight: 750g
Ideal for apparel, books, and flat items - Royal Mail Small Parcel
Max weight: 2kg
Suitable for most eCommerce shipments - Royal Mail Medium Parcel (Domestic Only)
Max weight: 20kg
Used for bulkier shipments
These categories are critical because even a small increase in thickness or dimensions can move a shipment into a higher pricing tier.
Custom Boxes in Shopify With Royal Mail Shipping
Custom boxes refer to packaging that merchants source independently rather than relying on predefined carrier formats.
For Shopify sellers, this means complete control over:
- Box dimensions
- Packaging material
- Branding and presentation
Common Custom Packaging Types
- Corrugated boxes for strong protection
- Poly mailers for lightweight apparel
- Rigid mailers for flat products
- Branded cartons for premium unboxing
Why Custom Boxes Matter for Royal Mail
Unlike flat-rate systems, Royal Mail pricing is dimension-sensitive. That makes custom packaging extremely valuable.
Benefits include:
- Reduced empty space
- Lower-dimensional thresholds
- Better product protection
- Improved customer experience
A well-optimised custom box can help keep shipments within Large Letter or Small Parcel limits, significantly reducing shipping costs.
Custom Boxes vs Royal Mail Carrier Boxes in Shopify: Comparison
For Shopify merchants, the choice comes down to cost control vs operational simplicity.
| Factor | Custom Boxes | Royal Mail Carrier Sizes |
|---|---|---|
| Packaging cost | Paid separately | No dedicated carrier boxes |
| Size flexibility | Fully customizable | Fixed category limits |
| Product fit | Excellent for unique items | Best for standard sizes |
| Shipping efficiency | Optimized per product | Faster classification |
| Rate impact | Can reduce costs via sizing | Risk of tier jump if oversized |
| Packing speed | Efficient after setup | Faster for repetitive orders |
When to Use Royal Mail Carrier Boxes vs Custom Boxes
Use Royal Mail Size Categories When:
- Products naturally fit within Letter or Large Letter dimensions
- You ship high volumes of similar items
- Speed of packing is a priority
- You want predictable pricing tiers
This is ideal for books, documents, and apparel.
Use Custom Boxes When:
- Products have irregular shapes
- You want to stay under size thresholds (critical for Royal Mail pricing)
- Items are fragile and need tailored protection
- Branding and presentation matter
Custom packaging is especially useful when trying to avoid upgrading from Large Letter to Small Parcel, which can significantly increase costs.
How to Enable Custom and Carrier Boxes in Shopify
One good solution to manage multiple packaging options and shipping with them is the PH Multi-Carrier Shipping Label app.
Step 1: Install the PH Multi-Carrier Shipping Label App
To get started with Royal Mail shipping in Shopify, the first step is to install the PH Multi-Carrier Shipping Label from the Shopify App Store.
Step 2: Configure Custom Boxes In The App
Head to the packaging settings of the app and click on the “add box.”
- Add box name
- Enter dimensions (L × W × H)
- Add empty weight
- Define maximum weight
This allows you to tailor packaging for each product type.
Step 3: Add Royal Mail Standard Box
You can configure these exact Royal Mail categories in packaging settings by clicking “add box” and clicking on Royal Mail:
- Royal Mail Letter
- Royal Mail Large Letter
- Royal Mail Small Parcel
- Royal Mail Medium Parcel (Domestic Only)
Step 4: Finalise Packing and Print Labels
Once the setup is done in the PH Multi-Carrier Shipping Label, everything works automatically.
- When an order is placed, the app selects the best box (custom or Royal Mail)
- You can directly generate the shipping label using that selection
That’s it: faster packing, accurate rates, and no manual work.
Royal Mail Packaging Scenarios: Real Shopify Examples
Apparel Store
- T-shirts – fit within Large Letter using slim mailers
- Bulk orders – move into Small Parcel
- Best approach: Custom mailers plus Royal Mail Large Letter optimisation
Electronics Store
- Small gadgets need protective packaging
- A slight size increase can trigger higher pricing
- Best approach: Custom boxes sized precisely to stay within Small Parcel
Handmade Products Business
- Irregular shapes don’t fit standard dimensions
- Branding is important
- Best approach: Custom packaging for fit + presentation
Subscription Box Business
- Predictable monthly shipments
- Consistent dimensions
- Best approach: Predefined custom boxes aligned with Small Parcel limits
Conclusion
Smart packing with Royal Mail comes down to choosing the right size category while keeping packaging efficient.
Custom boxes help reduce space, protect products, and avoid higher pricing tiers, while Royal Mail categories keep shipping simple and predictable.
Most Shopify merchants benefit from a mix of both. Using tools like PH Multi-Carrier Shipping Label, you can automate box selection and label generation, making shipping faster, cheaper, and more efficient.
FAQ’s
Q. Can you get free boxes from Royal Mail?
No, Royal Mail does not provide free boxes or general packaging materials to customers. If you need boxes or packaging supplies, you can purchase them directly from the Royal Mail online shop.
Q. Does Royal Mail deliver to India?
Yes, Royal Mail delivers to India, offering multiple international shipping services for letters, documents, and parcels.
- Standard international delivery usually takes 5–7 working days
- Economy services may take up to 12 weeks
Q. What is a Royal Mail parcel box?
A Royal Mail parcel box, also known as a parcel postbox, is a special type of postbox provided by Royal Mail designed to accept small to medium-sized parcels. Unlike standard letter postboxes, parcel postboxes have larger openings, allowing you to drop off packages as well as letters, making them convenient for sending pre-labelled shipments without visiting a post office.
