Purple Post vs Royal Mail
The short answer
With Purple Post, a message with 3 photos and a reply costs from 50p, sent from your phone. A letter with a stamp for the reply costs £1.82 in second class stamps, plus paper, an envelope, printing your photos and a trip to the post box. Purple Post is available at HMP Parc, HMP Five Wells and HMP Rye Hill. Post reaches every prison.
Side by side
| Feature | Purple Post | A letter by Royal Mail |
|---|---|---|
| Message with a reply | From 50p (£1.25 if you buy a single credit) | £1.82 for two second class stamps at 91p each, plus paper and an envelope |
| Photos | Up to 3 included | You print and post them yourself |
| How you send it | From your phone | Write it, print any photos and walk to a post box |
| How long it takes | Sent to the prison straight away, then subject to prison checks | Days each way, plus prison checks |
| Reply | Included, and you get a notification | Comes back by post |
| Carbon emissions | No letter to deliver (printed on site at HMP Rye Hill). We have not measured the footprint of sending a message | About 19g of CO2e to deliver each letter, before paper and printing (Royal Mail Wholesale figure for 2024/25) |
| Prisons | HMP Parc, HMP Five Wells and HMP Rye Hill | Every prison |
| Legal letters | Not suitable | The right choice for legal mail |
Each week, a person in prison can send one free letter, or two if they are on remand. If they use it to reply, you would need only one stamp. Most letters are checked by prison staff, and cards posted by family are photocopied. See the GOV.UK guidance on letters.
Which is right for you?
Purple Post may suit you if
- The person you're writing to is at HMP Parc, HMP Five Wells and HMP Rye Hill
- You want to send photos without printing them
- You want a reply quickly and without buying stamps
A letter may suit you if
- The person you're writing to is at another prison
- You're sending legal mail
- You don't have a smartphone, or you'd like to send something handwritten
Get started with Purple Post
Available at HMP Parc, HMP Five Wells and HMP Rye Hill. If your loved one is at another prison, register your interest.
Last checked: 8 November 2026. Rules and prices can change, so please check with the prison or provider.