GUIDE
How to send a letter to a federal inmate in the U.S.
A letter to a U.S. federal facility almost never gets lost in the mail. It gets lost at the envelope: an incomplete address, one photo too many, the wrong paper. Here is what gets through and what comes back.
The address needs three things, and none are optional
Incoming mail to a federal facility needs the person's full legal name, their eight-digit federal register number, and the facility's current mailing address. Without the register number the letter is returned or destroyed unopened — several people in one facility share a last name, and staff do not guess.
Register numbers are public. The Bureau of Prisons inmate locator at bop.gov/inmateloc searches by name and returns the register number, the facility, and the age. It is free and needs no account.
What gets it rejected
- Anything but plain white paper: card stock, colored paper, greeting cards, scented paper.
- Glitter, stickers, tape, staples, paper clips, smearing ink, crayon or heavy marker.
- Polaroids, photos with adhesive backing, nude or sexual photos, more photos than the per-envelope limit.
- Cash, loose stamps, pre-paid envelopes, anything of value.
- Content that threatens, harasses, or describes a crime — that is not just rejected, it is kept.
All incoming mail is opened and read
Except for clearly marked legal mail from an attorney, staff open and inspect every letter. There is no envelope privacy. Write as if a third party will read it, because one will.
There is no delivery receipt for incoming mail
This is the part that trips everyone up. Certified mail and signature tracking exist for mail an inmate sends out. For mail the public sends in, no facility confirms to an outside person that a letter reached the addressee's hands. What can be known: that the postal service accepted it, and that it did not come back. Any service promising you delivery confirmation inside a prison is selling something that does not exist.
Sending from outside the United States
You can send from anywhere, but international mail to a federal facility takes longer, passes through more hands, and is rejected on format more often. That is why many people living abroad have the letter printed and mailed from inside the United States instead.
Common questions
- How long does a letter take to reach a federal prison?
- The postal leg usually runs three days to two weeks within the United States. After that the facility has its own inspection process, and that timing is neither public nor uniform.
- Can I send photos?
- Generally yes — ordinary paper photos, no adhesive backing, nothing sexual, within the facility's per-envelope limit. Polaroids are almost always rejected.
- Will I be told the letter was delivered?
- No. No federal facility confirms to an outside sender that incoming mail reached the addressee. You can only verify that the postal service accepted it and that it was not returned.
- Do I have to put a return address?
- Yes. Mail without a complete, legible return address is returned or discarded, and the return address is the only way a rejected letter comes back to you.
You can write to Diosdado now and we keep it, free, until there is a verified mailing address. Or post it on the public wall. Write it →