T-Mobile is no stranger to making big moves in order to attract new sign-ups. That's been its MO for the last few years as it slowly leaches subscribers away from the other carriers. Tmo's service hasn't been as good of a deal lately, but there's a very intriguing promotion starting March 1st. T-Mobile will give most subscribers a free line.

This deal is available to most new and existing customers. Anyone on ONE or Simple Choice plans can get the free line, provided there are two or more lines already. For capped simple choice plans, the bonus line will have the same amount of monthly data as your voice lines. If they have different amounts, it will match the lower of the two. The extra line can be for a smartphone, tablet, wearable, or even an in-car hotspot. T-Mobile is obviously hoping you'll buy a new device for the bonus line, but it doesn't sound like you are required to.

As with many of these "free" line promotions, this is free after a bill credit. However, T-Mobile says you should see that on the first bill. If not, the second bill will have two credits to make up for it. While the promotion starts on March 1st, we don't know how long it'll be available. You can keep the free line for as long as you want, provided you keep the eligible lines active.

Press Release

Bellevue, Washington — February 27, 2017 — T-Mobile is about to thank you like you’ve never been thanked before! Starting Wednesday, March 1st, T-Mobile (NASDAQ: TMUS) is giving current customers an ENORMOUS thanking with an additional line of service—absolutely FREE. Virtually every T-Mobile customer with at least two voice lines can get an additional line for free after bill credits.

“Today, I’m thanking customers by giving them one of the things they want the most – a way to connect more of their family or more of their devices all the time,” said John Legere, president and CEO of T-Mobile.  “That’s why we’re giving customers a free line to use any way they choose!”

Current Un-carrier customers with at least two voice lines can use that extra line however they want. Get an extra line of unlimited T-Mobile ONE. Or if you have Simple Choice, you’ll get an extra Simple Choice line with your same data plan. Or use your free line for a new tablet or smartwatch. Or turn your car into a 4G LTE hotspot and a lot more with SyncUp Drive. It’s your call!

Right now, combined with the Un-carrier’s offer of two lines of T-Mobile ONE for $100, getting an extra line free means you can now get THREE lines of T-Mobile ONE for that same $100 a month with AutoPay!

This offer applies to all those with T-Mobile ONE, Simple Choice and Simple Choice No Credit plans – almost anyone with two or more postpaid voice lines. Even small businesses with up to 11 lines can get in on the deal on their T-Mobile @Work account.

While this deal will be available for a limited time only, you can keep your free line as long as you’re on an eligible T-Mobile plan and in good standing or until you make changes. To add your free line, just walk (or run) into any participating T-Mobile store.

For more information, please visit www.t-mobile.com/offers/3rdLineFree.