Optimise packaging for Royal Mail postage sizes and save costs

Optimise packaging for Royal Mail postage sizes and save costs

2025/08/01

No matter what type of packaging you are looking to buy, here at BiGDUG we understand that you are most likely trying to keep costs low. In the current climate, individuals and companies are finding themselves under a significant amount of financial pressure.

Whether you are filling up your car with fuel, conducting your daily shopping, or searching for reliable suppliers for packaging, it is only natural you want to find a cheap yet trustworthy option. We know that Royal Mail postage sizes can be a minefield and, if your packaging options are not considered, keeping up with costs can be tricky.

A solution, such as using optimised packaging suitable for sending with Royal Mail, is a simple yet money-saving method that can reap benefits for your business – including increasing profits and keeping customers satisfied. With Royal Mail successfully delivering over 9.5 billion letters during the financial year ending in March 2021, the courier is a dependable and highly rated company that thousands of businesses trust to deliver their products.

Getting stock to consumers quickly and in good condition is a priority for all companies. Using Royal Mail-sized packaging is a cost-effective method of doing this. BiGDUG has put together a list of ways you can ensure that you can keep abreast of Royal Mail postage sizes, and ensure your products fit in the Royal Mail’s allowance, as well as which products you can buy from us that are suitable for sending with the carrier.

Become Box Smart

Packing smart means that you are making the most of your packaging and the price of postage. Postal costs, whether being sent 1st Class, 2nd Class or Royal Mail Signed For®, are all dependent on Royal Mail postage sizes and the weight of the contents. This means choosing the right packaging can help save your company quite a lot of money. To do this, make sure that you are getting thick, secure, and durable boxes that are the correct size. Packing your items tight and lowering the size of the package will be more advantageous for your business. Just because items are heavy doesn’t mean you have to get a larger box to help keep them secure, you can size down and lower postage costs by being able to fit under a smaller parcel category. If your item is classed as a Small Parcel, it will cost a lot less to send than a Medium Parcel, even if both products are the same weight.

If you want to learn more about Royal Mail postage sizes and weight classifications, click here.

Send Multiple Items in One Delivery

Suppose you choose to use Royal Mail’s Parcelforce Worldwide, excluding global value and global economy. In that case, you can send up to 15 items in one shipment and receive a significant discount on the delivery. This can help lower your postal costs significantly because instead of sending parcels individually for double the price, depending on what is being sent you can save a third or even half of the original postage cost if you send it as a consignment! All of which will increase your profits while still assuring your products are delivered quickly and efficiently – keeping customers happy.

Choose the Right Service for your Chosen Marketplace

If your package is marked as ‘item not received’ and you have chosen eBay as the marketplace where you want to sell your items, eBay requires proof of delivery for sales up to £750 and a delivery signature for the more expensive transactions. Royal Mail Special Delivery by 1 pm, Royal Mail Special Delivery by 9 am, Royal Mail Signed For services, and Parcelforce Worldwide services align with eBay’s seller protection guidelines for sales that surpass £750. However, you should always remember to check the compensation cover available when choosing the delivery service, therefore if there is any loss or damage, your company will be covered.

Claim your VAT

If your business is registered for VAT, and if you sell taxable goods or services, you’ll be able to recover the VAT you have spent during postage on your next VAT return. To read more about the VAT policies and whether your company is eligible for a return, read Royal Mail’s information on their VAT service charges here. If you discover that your packages are eligible for a VAT return, then you must never forget to ask for a VAT receipt whilst sending items. Standard postal services are usually exempt from this form of tax. However, if the delivery charges for your goods include buying stamps from the Post Office, you might have to include VAT in the cost of your products for the cost of postage.

Pick the right packaging to fit Royal Mail postage sizes with Help from BiGDUG

If you need packaging that is robust, durable, and secure, BiGDUG will have the perfect parcel type for you!

Royal Mail Large Letter Boxes

The maximum weight of this category is 750g, with a capped size of 35.3cm x 25cm x 2.5cm. This form of Royal Mail packaging is convenient for customers as it can be posted through their letterbox, so they never have to worry about missing a delivery. BiGDUG offers a wide variety of packaging that qualify as large letter boxes, which you can find here. From book boxes, flat cardboard boxes, mailing bags and jiffy bags, you can find a large selection of packaging that is secure and reliable for sending your goods in the post on our website. Your consumer base can be assured that their orders won’t be under threat due to being left outside by the door, and you will save money as a business by not having to overspend on larger parcel sizes. This category is a lightweight yet effective form of packaging.

Royal Mail Small Parcel Boxes

The small parcel sector equates to parcels that weigh no more than 2kg, and the dimensions cannot exceed 45cm x 35cm x 16cm. Generally, regular corrugated cartons and padded bags are the most popular form of packaging in this category. Postal tubes, book wrap mailers, larger cardboard boxes and self-seal postal cartons are also favourable choices for sending items in. By using parcels that fit under the Royal Mail small parcel guidelines, you can spend less money on postal costs due to not having to overpay or receive overcharges, and your customer can receive a lightweight, durable, yet attractive package.

Royal Mail Medium Parcel Boxes

Royal Mail’s guidelines state that parcels that fall into the medium boxes category should not weigh above 20kg, as well as not be larger than 61cm x 46cm x 46cm. One way of diminishing postal costs for medium boxes is by using mailing bags as they are of low weight, flexible, and can be bought in a range of sizes. If you need more security than mailing bags for your goods, here at BiGDUG, we have a large variety of postal boxes in fluctuating sizes, so you will find the perfect carton for your needs!

Royal Mail Large Parcel Boxes

This Royal Mail category accounts for heavy-duty, bulky items. Your boxes fall under this section if they weigh up to 30kg and measure 150cm x a combined width with a depth of 300cm. If your products are heavy, sharp or could easily work their way out of a smaller carton then this is the correctly sized packaging choice for you. It is the costliest category, however, the security of larger, double-walled boxes will guarantee that customers get their orders in one piece.

Even though it might cost you more at first, replacing your packaging to fit the correct Royal Mail postage sizes and categories will save you money and time with packing costs in the long run. Optimising packaging to fit specific postal sizes will ensure that all your postal boxes are securely protected which in turn, will increase customer loyalty. To buy high-quality packaging at a great cost, shop with BiGDUG today – we are a packaging supplier you can trust.

Contact Us

Looking for a bespoke solution? Speak to our Business Solutions team to find out more.