Royal Mail Postage Costs & Sizes 2026

Since 5 October 2026, a Royal Mail small parcel costs £5.90 1st class or £4.60 2nd class by stamp, or £5.70 and £4.40 when you buy postage online. Letter and large letter stamps haven't changed.

This complete guide pute ever Royal Mail postage cost, size and weight limit all in one place.

Royal Mail Sizes and Postage Costs at a Glance

As a rule, Royal Mail generally measures the packed item, and the first limit it breaks (length, width, thickness or weight) decides the format.

How much did Royal Mail prices go up in October 2026?

Depending on the service, parcel prices rose by between 25p and 65p. Letter and large letter stamps stayed at their April 2026 prices.

Buying postage online through Click & Drop is still cheaper than these prices, as each section below shows.

Royal Mail Small Parcel: Size, Weight and Price

What size is a small parcel?

A small parcel can be anything up to 45 × 35 × 16cm and weigh up to 2kg. Exceeding any of these limits, even by just 1cm, means your item will be classified as a medium parcel, resulting in higher postage costs.

For clothing and other soft goods, our printed polythene mailing bags provide a lightweight packaging option. This is the format that matters most for: clothing, books, cosmetics and most shoes all fit comfortably. See our shipping bags for clothes for mailers designed to help fashion and apparel brands.

How much does it cost to send a small parcel?

From £3.75 with Tracked 48 bought online, or £4.60 with a 2nd class stamp.

The price is flat all the way to 2kg, so a 200g T-shirt costs the same to post as a 1.9kg pair of boots. Bought online, every service is cheaper. Tracked 48 online undercuts a 2nd class stamp by 85p, with tracking included.

Is a shoe box a small parcel?

Usually, yes. Most shoe boxes are roughly 33 × 19 × 10cm for women's shoes and 35 × 25 × 13cm for men's, well inside the limits. In fact, Royal Mail deepened the small parcel to 16cm in 2013 with shoe boxes in mind. Tall boot boxes are the exception: at 15–18cm deep, some tip over into a medium parcel.

Royal Mail Medium Parcel: Size, Weight and Price

What size is a medium parcel?

A medium parcel can be up to 61 × 46 × 46cm and 20kg, including the packaging. It covers anything too big or heavy for a small parcel, from bulk orders to homeware.

How much does a medium parcel cost?

From £7.00 2nd class online, rising in three weight bands.

Unlike a small parcel, weight changes the price here, so weigh heavier orders before you buy postage. Even so, Tracked 48 is again the better deal online: £5.70 up to 2kg, £7.55 up to 10kg and £12.25 up to 20kg.

What if my parcel is bigger than a medium parcel?

It goes by Parcelforce Worldwide instead. Parcelforce express48 takes parcels up to 30kg, 1.5m long and 3m in length and girth combined. Prices depend on the service and weight, so check Parcelforce or compare couriers before you book.

Tracked 48, Tracked 24 or Signed For: Which Is Best?

Is Tracked 48 cheaper than 2nd class?

Yes, when you buy it online. A Tracked 48 small parcel costs £3.75 online, against £4.40 for 2nd class online and £4.60 by stamp.

Which service includes a signature?

Signed For, Tracked with Signature and Special Delivery. For most sellers, Tracked 48 with Signature (£5.35 for a small parcel online) gives the best mix of proof, tracking and price.

How much compensation do I get?

Up to £20 for standard post and Signed For, £75 for Tracked, and £750–£2,500 for Special Delivery. In practice, anything worth more than £75 belongs on Special Delivery, which starts at £9.85 online for items up to 100g.

Royal Mail Large Letter: Size, Weight and Price

What size is a large letter?

A large letter can be up to 35.3 × 25 × 2.5cm and weigh up to 750g. Of those limits, the 2.5cm thickness catches people out most often. Overfill a mailing bag by as little as 0.5cm and it becomes a small parcel.

How much is a large letter stamp?

£3.30 1st class or £1.55 2nd class, up to 100g.

Keeping an order as a large letter is the simplest saving there is. By stamp, a 1st class large letter costs £2.30 less than a small parcel, and a 2nd class one £1.90 less.

Is A4 a large letter?

Yes. Flat A4 paper in a C4 envelope is a large letter.

Greeting cards follow the same rules. Square cards carry no extra charge in the UK, as long as they fit the letter or large letter limits.

Can I track a large letter?

Yes, online. Tracked 48 costs £2.90 and Tracked 24 £3.90, and bought online a tracked large letter can weigh up to 1kg rather than 750g.

Royal Mail Letter: Size, Weight and Stamp Prices

What size is a standard letter?

A letter can be up to 24 × 16.5 × 0.5cm and weigh up to 100g. One sheet of A4 paper weighs about 5g, so for most letters and cards the 5mm thickness limit applies long before the weight limit does.

How much is a stamp in 2026?

A 1st class stamp costs £1.80 and a 2nd class stamp 91p. Neither changed in October.

Since Ofcom's 2025 reforms, 2nd class letters arrive on alternate weekdays and no longer on Saturdays. In October 2026, the Communication Workers Union said Royal Mail was losing around 400 postal workers a week since the new delivery system began, according to BBC News. You can combine stamps to make up the right value. That said, regular stamps without a barcode are no longer valid (although you can exchange them free through Royal Mail's Stamp Swap Out scheme).

Packing to Fit: Measure the Filled Bag

How do I measure a filled mailing bag?

Pack it, seal it, then measure it at its thickest point. Royal Mail measures the item as posted, not the empty bag. Filled, a mailing bag loses some length and width as it wraps around the product, while its thickness depends entirely on what's inside.

For a quick check on large letters, cut a 2.5cm slot in a piece of card: if the packed item slides through, it's a large letter. For clothing and soft goods, paper mailing bags offer a slim paper alternative to polythene.

What happens if I underpay?

Royal Mail charges your customer a Fee to Pay before it delivers the item.

For a medium parcel, the fee is £1.50 plus the postage owed. Anything bigger than 61 × 46 × 46cm or heavier than 20kg costs an extra £10.

Which Mailing Bags and Boxes Fit Royal Mail Sizes?

Which mailing bag fits a large letter?

A 10 × 13" mailing bag or a letterbox mailing box keeps flat orders in the large letter band. Above those sizes, most bags and boxes post as a small parcel.

Our printed mailing boxes are built around Royal Mail's size limits, so there's no guesswork at the post office.

What size mailing bag do I need for clothes and shoes?

For most clothing, a 10 × 13" or 12 × 16" bag. However, the thickness of the folded item decides the format.

Not sure which size suits your products? Our guide on how to choose mailing bags for ecommerce walks through it, and our printed mailing bags come in sizes for everything from large letters to medium parcels.

Royal Mail Postage FAQs

Is it cheaper to buy postage online?

Yes, for parcels and for 1st class large letters. Through Royal Mail Click & Drop, a small parcel costs 20p less than by stamp and a medium parcel 50p less. You can drop labelled items at a postbox, parcel postbox or Post Office, or have them collected for 50p per item.

What size is a UK letterbox?

There's no single UK size. The British and European standard (BS EN 13724) recommends a slot that takes a C4 envelope without bending, with an opening 30–35mm high. As a result, a full 2.5cm large letter fits most modern letterboxes, though older doors can be tighter.

When is the last posting date for Christmas 2026?

Monday 21 December for 1st class, and Friday 18 December for 2nd class.

Business account holders should also budget for Royal Mail's peak surcharge, which runs from 2 November 2026 to 10 January 2027 and adds 10p–30p per item to most contract parcel services. Stamps and postage bought without a business account aren't affected.

Are old stamps still valid?

Regular stamps without a barcode are not. Christmas and special stamps without a barcode still are. You can swap old regular stamps for barcoded ones free through Royal Mail's Stamp Swap Out scheme.

Packaging that fits Royal Mail sizes, with your brand on it

Getting the size right is the easiest postage saving there is. Our mailing boxes are built around Royal Mail's size limits, and our printed mailing bags come in sizes for everything from large letters to medium parcels. Tell us what you're sending and we'll recommend the size that keeps your postage down.

Build your bag · Call 01438 873840