Stamps in prison are ordinary U.S. postage stamps that do two jobs at once: they pay for outgoing mail, and they function as the informal currency inmates use in place of the cash they are forbidden to hold. A single Forever stamp costs $0.78 at the commissary, and at prison wages that can start around $0.14 an hour, that small square carries real purchasing power.
Why Stamps Became Currency
Federal law classifies U.S. or foreign currency as a “prohibited object” inside prisons, and possessing it is a criminal offense.1Office of the Law Revision Counsel. 18 U.S. Code 1791 – Providing or Possessing Contraband in Prison Inmates still need a way to exchange value with each other, and stamps filled the vacuum. They are small, portable, universally recognized, priced the same for everyone, and resupplied regularly by the commissary. In many facilities a book of stamps functions roughly the way a $20 bill does on the outside, changing hands for food, haircuts, laundry, tutoring, and favors.
The underlying postage still matters too. Written letters remain the cheapest and most reliable way for incarcerated people to stay in contact with family, friends, and lawyers, and a stamp is what makes that letter move.
How Inmates Buy Stamps
The commissary is the source. In the federal Bureau of Prisons, the commissary sells Forever stamps and may stock up to five denominations covering domestic letters, international mail, and packages. Inmates generally cannot buy more than 20 first-class stamps per commissary trip, though a warden can raise that limit when commissary visits are restricted to once a week or less.2Federal Bureau of Prisons. Trust Fund/Deposit Fund Manual
Payment comes from the inmate’s trust account, a debit-style account the facility manages. Money flows in from three places: deposits by family and friends through electronic transfers, mailed money orders, or in-person deposits where allowed; and wages from a prison job. Those wages are small. Regular prison jobs pay roughly $0.14 to $0.63 an hour, and correctional industries positions pay about $0.33 to $1.41 an hour. A book of 20 Forever stamps at $0.78 apiece is several days of work at the lower end.
One restriction catches a lot of families off guard: stamps have to come from the institution or the commissary. Inmates cannot receive stamps mailed in from the outside.3eCFR. 28 CFR 540.21 – Payment of Postage The rule keeps the stamp supply inside each facility controlled and auditable.
If an Inmate Has No Money
Federal regulations require the warden to provide free postage for legal mail and for administrative remedy forms when an inmate has neither funds nor stamps. The warden also has to supply stamps for a “reasonable number” of personal letters so the inmate can maintain community ties, and for emergency correspondence when staff can verify the emergency.3eCFR. 28 CFR 540.21 – Payment of Postage State systems often claim similar indigence policies, but who qualifies and how much they receive varies widely from one system to the next.
How Many Stamps You Can Keep
Facilities cap possession. In the federal system, local guidelines set by the warden limit each inmate to no more than 60 first-class domestic stamps or the equivalent value in other denominations.4Federal Bureau of Prisons. Program Statement 5265.014 – Correspondence A warden can approve a higher cap for a particular inmate. The default ceiling exists because a large stockpile looks less like personal correspondence and more like inventory for the informal economy.
State limits run on their own numbers. Some systems cap possession at 20, others allow more. In any system, going over the limit can mean confiscation of the excess and a disciplinary write-up.
Trading Stamps Is Against the Rules
The stamp economy is widely known and widely practiced, and it is also explicitly prohibited. Federal regulations list giving or accepting anything of value to or from another inmate without staff authorization as a moderate-severity prohibited act. Running a business and loaning property for profit are listed alongside it.5eCFR. 28 CFR 541.3 – Prohibited Acts and Available Sanctions
Enforcement is uneven, but the consequences when it does come down are real: an incident report, loss of privileges, a housing move, or disqualification from programs. High-volume trading and disputes that boil over are what tend to draw staff attention. Debts in the stamp economy carry their own hazard, since owing stamps and failing to pay can lead to intimidation or violence. That dynamic is part of why facilities try to limit both how many stamps an inmate can hold and how freely they can move between inmates.
Digital Mail Is Changing the Picture
Physical mail in prisons is shrinking. Drugs can be sprayed onto paper, worked into ink, or hidden under stamps, and that threat has pushed facilities toward digitizing incoming correspondence.6National Institute of Justice. Mitigating Contraband via the Mail – An Overview of Approaches for Managing the Introduction of Drug Contraband through the Digitization of Inmate Mail As of 2025, at least 25 state prison systems photocopy or scan incoming mail, along with the federal Bureau of Prisons in facilities above minimum security.7Prison Policy Initiative. Mail Scanning: A Harsh and Exploitative New Trend in Prisons Letters are routed to a processing center, converted to digital images, and delivered through tablets, kiosks, or printed copies. The original is stored or destroyed.
Electronic messaging platforms have grown alongside this. Services such as JPay sell digital “stamps” that inmates use to send and receive electronic messages, commonly around $0.35 to $0.50 per message depending on the facility. Physical postage stamps are still needed for outgoing mail in most facilities, so they continue to matter both at the mailbox and inside the informal economy, but their role on the incoming side is shrinking.