Here you will find detailed information including sizes and costs for sending standard letters and large letters with Royal Mail.
May be used for U.S.P.S. Residential door mail delivery; Made of brass; Letter size mail slot overall dimensions are 8-3/4' W x 2-7/8' H; Rough opening dimensions are 6-7/8' W x 1-3/4' H; Include an 8' W x 2' H spring loaded flap; Include 2 pieces - flap for the front of a wall or solid door and inside trim for the rear.
Royal Mail Size & Weight Guide For Letters
| Max Weight | Max Length | Max Width | Max Thickness | |
|---|---|---|---|---|
| Letter | 100g | 24cm | 16.5cm | 5mm |
| Large Letter | 750g | 35.3cm | 25cm | 2.5cm |
- RM Postie here - there is no standard size for the opening in the post boxes as it depends entirely on where its sighted, the type of box and if it is at a busy location. However most are usually.
- The slot in a pillar box is about 25cm x 7.5cm. Slot, thats the word I was looking for, I knew I shouldn't be calling it a mouth. Thanks for the info, should get my package in, saves me having to go to the post office tomorrow morning.
- Royal Mail size guidelines say a small parcel is anything that fits in a 35cm by 45cm by 16cm space. I have some boxes that are 23cm by 20cm by 16cm so two lengths are well within the guidelines and one is just in. If the box buckled out the way this could potential lead to it being out the guidel.
Letters
Ideal for mailing greeting cards, regular letters and postcards, the maximum size that would fall under a 'letter' is 165 mm x 240 mm. We would recommend using an envelope no larger than C5 to fit these restrictions comfortably and avoid any excess costs. The envelope and contents must also weigh under 100g.
Royal Mail Slot Sizes
Recommended envelope sizes
Royal Mail Slot Size Chart
Cost for sending a letter
| Service | Price |
|---|---|
| 1st Class | 76p |
| 2nd Class | 65p |
Large Letters
For mailing contents such as A4 sized documents, DVDs, certificates, large greeting cards and magazines you would need to send as a large letter. The maximum size is 250 mm x 353 mm and and a maximum weight of 750g so a C4 envelope is a good choice.
Recommended envelope sizes for a large letter
Cost for sending a large letter
| Weight | 1st Class | 2nd Class |
|---|---|---|
| up to 100g | £1.15 | 88p |
| 101g to 250g | £1.64 | £1.40 |
| 251g to 500g | £2.14 | £1.83 |
| 501g to 750g | £2.95 | £2.48 |
Royal Mail Letter Size Guide Template
Letter, Large Letter, small parcel or parcel?
In 2006 the Royal Mail decided to follow other country’s postal system by introducing Pricing in Proportion. This was a system of charging different amounts for different size letters and packages.
Up until 2006 the Royal Mail charged by the weight of the item now it was to charge by weight and size. To enable the customers….especially business customers to access the correct size of a letter or package a Letter Size Guide template was introduced.
To begin with these were sent out by the Royal Mail in flimsy paper and if you were lucky you could get a limited cardboard version.
Today several years later there are many different versions of the Royal Mail Letter size guide available. See here for a selection.
Most of the letter size guides are made from perspex and do have ability in some cases to break or split easily. However the Royal Mail have there own modern version made of very strong plastic and you can see these in the Post Offices up and down the country. You can also buy these Royal Mail Letter size guides and in deed the other versions from Ebay and Amazon.
The first slot is for all mail in letter size, usually a DL, not being thicker than 5mm. The letter MUST pass freely through otherwise it may be considered a Large Letter.
Large letters must again pass through without getting stuck and goes up to 25mm in thickness.
If your mail does not fit either slot it is then becomes a small or large parcel.
Small parcel is items to be posted up to the size of 2 kg in weight, 35cm in length, 25cm in width and 16cm in length. Any thing bigger is a Large Parcel.
Letter size guide s are very useful to anyone who send s out post on a regular basis. Especially Offices, Schools, Doctor Surgery’s, Dentists etc. Even if you have a Franking Machine,as they do not have a Letter Size guide supplied with them. Many members of the public have a Letter Size guide so they can make sure the birthday card with a cheeky badge on it is sent with the correct postage on it.
If the letter or package does not have the correct postage on it the recipient can only obtain the letter by paying an extra £1.20plus the difference of postage between what was placed on the package and the next 2nd class price point.
Pricing in proportion only affects mail posted in the UK going to an UK address. This includes the Channel Islands, Isle of Man and Northern Ireland.
The slots on the letter size guide are not required for mail being sent to Europe or Internationally. This includes the Republic of Ireland.