What is a large letter?
A large letter in Royal Mail terms is anything that’s bigger than the size of a standard letter but still flat enough to fit through a letterbox. Think of an A4 envelope, a small brochure or even a birthday card with a few extras tucked inside. To count as a large letter, it must be no thicker than 2.5cm, no heavier than 750g and within 35.3cm x 25cm in size. It’s a category designed for that in-between kind of post—bigger than a simple letter, but not quite a parcel.
Current cost of a large letter stamp
As of 2025, a first class large letter stamp costs £2.20, and a second class large letter stamp costs £1.55. These stamps are designed specifically for the large letter category, covering up to 100g in weight. If your item is heavier, you’ll need to pay more based on the next weight band—but for most everyday post like documents and greetings cards, the standard large letter stamp will do the trick nicely.
Why large letter stamps are different
Large letter stamps aren’t just more expensive because they’re bigger—they also account for handling, space in sorting machinery and careful delivery. These items need a bit more room and care in the system, and the price reflects that. Unlike standard stamps which just say “1st” or “2nd”, large letter stamps are usually purchased with the amount already printed, or you may use printed postage from a post office or online.
How to weigh and measure at home
If you’re unsure whether your post counts as a large letter, it’s worth having a little scale and ruler to hand at home. A quick weigh-in can save you from underpaying, which could result in the recipient having to pay a surcharge. Royal Mail’s size guides and printable templates can help too—and many post offices have a slot-size gauge if you need to check in person.
Can I use regular stamps to cover the cost?
Yes, you absolutely can use multiple standard stamps to make up the cost of a large letter. For example, if you’re sending a first class large letter and only have 1st class stamps worth 85p, you can simply use three stamps to cover the total. It’s a helpful trick when you don’t have a large letter stamp to hand, and it’s perfectly valid as long as the total value is right.
Summary
A large letter postage stamp currently costs £2.20 for first class and £1.55 for second class, covering most A4-sized items up to 100g. Designed for that lovely middle ground between a letter and a parcel, it offers a simple and reliable way to post something slightly bigger with ease. Whether it’s a form, a card or a little surprise in the post, large letter stamps help you send it off with confidence and care.