Pen pal rules by state
Most U.S. prison systems have no rule against being listed on a pen pal site. Florida, Indiana, Missouri, Pennsylvania, South Carolina, Texas do (Texas only for sentences that require sex offender registration). Each rule below is quoted from the department's own policy, and each state page also explains how mail and electronic messages reach people there.
Updated by Jason Santiago
Systems with a pen-pal rule
Florida rule
Florida bans incarcerated people from placing ads for pen pals, including ads placed for them by someone else, and can discipline them for it. They can still write to pen pals they already know.
Indiana rule
Indiana bans incarcerated people from placing ads soliciting pen pals, including ads posted with someone else's help, and can discipline them. They may still write to pen pals.
Missouri rule
Missouri DOC tells families not to sign a loved one up for websites that solicit pen pals and says this is prohibited by department rules.
Pennsylvania rule
Pennsylvania forbids people in its prisons from buying advertising services, and names pen-pal advertising specifically. The rule does not mention listings paid for by family, but the department could treat one as breaking it.
South Carolina rule
South Carolina bans incarcerated people from placing ads soliciting pen pals, including ads posted with someone else's help, and can discipline them. They may still write to pen pals.
Texas rule
Texas bars anyone serving a sentence that requires sex offender registration from being advertised on a pen-pal website, even when someone else places or pays for the ad. For everyone else, Texas has no rule against being listed.