Query on British Passport - Sending supporting Document to HMPO

Prasath897 wrote: ↑

Thu Jan 22, 2026 11:25 am

Hi All,

I'm making a first adult British passport application.
Now I will need to send supporting document(Current passport and naturalization certificate) to passport office.

1. Which Royal Mail method to use to send the supporting document to passport office?
Personally I use Special Delivery Next Day 1pm which is fully tracked. But the choice is yours of course, but remember these are valuable documents.
2. Can I use A4 size envelope to put both Passport and Naturalization certificate together in a single envelope?
You can, but be aware that doesn't guarantee the certificate won't be bent/crumpled on the way there and back to you.
3. Do I need to put return envelope with a self addressed inside the supporting document envelope?
No - it won't be used.
4. on the Envelope I'm sending for supporting document, can I just add passport office address and PEX number on the front?
Yes. What else would you put apart from "Please don't bend"?
5. if i pay extra £5 for secure return, would that be sufficient to get the supporting document back?
That's what HMPO charges for their (optional) return service which is not necessarily Royal Mail. Otherwise they just use normal mail/their ordinary mailing company.

Just generally, I would photograph everything (not just copy) you are putting in the envelope and envelope itself.
Please anyone advice,

Thank you.

Prasath897 wrote: ↑

Thu Jan 22, 2026 11:25 am

Hi All,

I'm making a first adult British passport application.
Now I will need to send supporting document(Current passport and naturalization certificate) to passport office.

1. Which Royal Mail method to use to send the supporting document to passport office?

2. Can I use A4 size envelope to put both Passport and Naturalization certificate together in a single envelope?

3. Do I need to put return envelope with a self addressed inside the supporting document envelope?

4. on the Envelope I'm sending for supporting document, can I just add passport office address and PEX number on the front?

5. if i pay extra £5 for secure return, would that be sufficient to get the supporting document back?

Please anyone advice,

Thank you.