T-Mobile is trying to attract customers from its competitors with aggressive holiday sales. It recently tried to poach Sprint subscribers with a $200 bonus. Now it has an offer for folks who pay for AT&T service.

T-Mobile said Thursday that beginning Friday, December 4, it will give $200 to AT&T customers who port a line over to T-Mobile, sign up for an eligible Simple Choice Plan and buy the 128GB iPhone 6s, which brings the cost down closer to the 16GB model. The promotion is offered as a $200 bill credit that may take up to 90 days to hit your account, so it’s not immediate cash in your hand. T-Mobile is also offering steep discounts on accessories, including the Apple Watch, so long as you sign up for a financing plan and the product is priced between $69 and $250. You’ll owe the full cost on that accessory if you decide to cancel your plan within 24 months.

The T-Mobile offer is good for one device per line, and is open to AT&T, GoPhone and Cricket customers beginning December 4 and running through December 13.