Credit: Joe Maring / Android AuthorityTL;DRT-Mobile is offering some customers a free line as a limited-time promotion — though taxes, fees, and device connection charges apply.Users who accept the free line will have to Bring Your Own Device (BYOD) and note that promotional limitations will apply to that free line.Reddit users suggest verifying eligibility carefully through support channels and checking billing statements before activating new SIMs.T-Mobile does have some great plans and offers, but the carrier also hiked prices on its legacy plans earlier in the year. To soften the blow, the company rolled out a targeted promotion giving some users a free voice line. If you missed out on the offer back then, T-Mobile is now offering some users a free line, so it’s worth checking if you are eligible. There are also some catches that you should keep in mind before accepting the free line.Several Reddit users (1, 2, 3, 4) report receiving an email or text from T-Mobile informing them that they are eligible to add a free line to their account.