Her Majesty's 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, laid on 13 March 2018.
The Ministry of Defence has been allocated £12.7 million in 2018-19 for essential EU exit preparations. As with all HMT Reserve funding, finalised allocations will be confirmed at Supplementary Estimates 2018-19 in early 2019.