More than 300 new police officers and staff are to be recruited in Northern Ireland by 2020 for Brexit preparations, the force has said.
The PSNI has received a £16m windfall from the Chancellor.
It will be responsible for policing the border after the EU divorce.
Chief Constable George Hamilton said: "Since the referendum result, PSNI has been working with our partners to ensure we are in the best position possible to respond to any changes presented by Brexit.
"We welcome this additional funding which will allow us to recruit a total of 308 additional officers and staff by April 2020 and make some investment in our estate, IT and infrastructure.
"The ethos of policing with the community has been central to our planning and I want to reassure the communities we serve that this money will be used to keep people safe, by preventing harm, protecting people and bringing offenders to justice."
Policing Board chairwoman Anne Connolly said: "Resources available to the PSNI and their allocation to day-to-day delivery of the policing service is one of the key issues that the board will be discussing with the Chief Constable in the new year and in the development of policing plans for the time ahead."
Secretary of State Karen Bradley said the extra money would help the PSNI manage pressures arising from EU exit preparations and reflect the unique and specific concerns in the region.
"The UK Government has invested significantly in the PSNI, with over £230m of additional security funding over the course of the 2010 parliament and £131m over the current spending review period."
The Police Federation for Northern Ireland welcomed the money, but insisted funding needs to be kept under constant review.
Chair Mark Lindsay said: "This allocation is welcome and allays some of our concerns. Preparing for Brexit is a task of monumental proportions with many unknowns.
"If the UK crashes out at the end of March, there will obviously be significant additional pressures placed on our officers.
"The implications are immense. This money will deliver hundreds more officers and staff but the allocation shouldn't be taken to mean that is the end of the matter. It may very well be the case that in response to issues thrown up by a hard exit of the EU that further additional financial resources will be required.
"There is a need to be responsive and flexible. If there is a clear and undeniable case for more officers, then ministers will have to come back with what is required.
"We feel that the additional money is a welcome boost, but we are duty bound to point out that we are entering uncharted waters where there may well be further requests for financial assistance.
"Contingency planning has to be stepped up in line with what the Government has already announced.
"Serious consideration must be given to the specific requirements of Northern Ireland where our officers will be expected to undertake frontier duties in support of other Government agencies in the event that there is no deal by March 29.
"It's time to get real about Northern Ireland's security requirements and the resources that will be required."