Assuming you mean you have paid £2,880 as a "relief at source" contribution (the standard system for SIPPs) then that makes it a gross contribution is £3,600 and your basic rate band is extended from £37,700 to £41,300 (plus Personal Allowance).I should add that I have a Sipp which is funded to the tune of £2880 every year.
So no higher rate tax payable on the first £53,870.