HM Treasury has already allocated over £4.2 billion of additional funding to departments and the devolved administrations for EU exit preparations so far. This includes the £1.5 billion of additional funding HM Treasury announced at Autumn Budget 2017 for 2018/19. A full breakdown of how this was allocated to departments can be found in the Chief Secretary’s Written Ministerial Statement, HCWS540:
This money will be paid out in Supplementary Estimates 18/19 later this financial year.
The Office holds no estimate of what it has spent on no deal preparations which can readily be separated from other EU exit and devolution work in general.