T-Mobile USA, long trailing its rivals in the cellphone industry, is trying to catch up by changing the conversation: it is selling the iPhone cheaper than the competition, and most important, customers would not have to sign a contract.

But it may not be enough to persuade smartphone users to abandon the competition.

Analysts said the new marketing strategy, which spreads the cost of a new phone over two years as a separate line item on the monthly bill, will still feel like a commitment to many customers, even if they can choose to pay it off early and walk away. And T-Mobile, which has a slower network than its competitors, is only just beginning to introduce major upgrades.

The company on Tuesday said the Apple iPhone 5 would be available starting April 12 for $100 up front, with customers paying an additional $20 a month for two years. Other new smartphones, like the Samsung Galaxy S 4 and the BlackBerry Z10, will be available with similar payment plans.

Although T-Mobile’s new phone plans require no long-term contract, customers would have to pay off the balance owed in order to end service prematurely.