T-Mobile announced the Why the Hike promotion for AT&T customers with grandfathered unlimited plans. The promotion nets those customers a $250 prepaid card if they make the switch. AT&T recently announced another price hike for its grandfathered unlimited plans for the third year in a row. If you are an AT&T customer with a grandfathered unlimited plan, you will soon feel the sting of yet another price hike. Alternatively, T-Mobile proposes that you simply jump ship and get some money for your troubles. Starting Wednesday, June 20, AT&T customers with a grandfathered unlimited plan can either visit a T-Mobile store or call to ask for the Why the Hike (WTH) deal. With the deal, those customers and anyone else on that plan through June 7 can port their number and get $250 on a prepaid card. They also get up to $650 through trade-in credit and prepaid card to pay off their contracts as part of Carrier Freedom, so long as they sign up for T-Mobile One. Originally unveiled in 2016, the plan charges $70 a month for the first line and includes unlimited calls, text, and 4G LTE data. The WTH promotion is for “a limited time,” though no end date was provided. The promotion is a clear shot at AT&T, which recently announced another price hike for grandfathered unlimited plans to $45 each month. The price hike is the third one in a row, one happening each year. Editor's Pick Here are the best T-Mobile prepaid plans right now While T-Mobile is trying to market its unlimited T-Mobile ONE plan to postpaid smartphone customers, there are still some T-Mobile prepaid plans that are available for people who don’t want to spend money on data they … At that rate, grandfathered unlimited plans will charge as much as the current cheapest unlimited plan in 2022. AT&T’s cheapest unlimited offering is its $65-per-month Unlimited Choice Enhanced. It is clear that AT&T wants to boot grandfathered customers off of those plans and will raise the monthly price every year until it attains its goal. T-Mobile predictably saw that and wants to capitalize on it, though how many will actually take up the carrier’s promotion is another question.