The UK stands to make £470m of annual cost savings after Brexit on redundant EU agencies, according to new research.
The UK currently pays around £620m annually through administrative contributions across 67 EU institutions.
But European law firm Fieldfisher has found that the UK could save £470m by no longer having to fund the running costs of around 21 EU institutions and agencies, including the European Parliament and the EU's diplomatic service.
However, the report has also warned of serious administrative challenges lay ahead for the UK civil service.
Co-head of Fieldfisher's regulatory group John Cassels said: "The administrative cost savings associated with Brexit do appear to be attractive.
“However, the reality is that the regulatory transition required to repatriate functions of EU agencies back to the UK is likely to be disruptive to regulated businesses and individuals, as well as to the UK civil service itself."
Research showed the UK government will need to contribute around £35m a year to part-fund a number of EU agencies with which the UK will need to maintain a strategic partnership.
These include those which regulate aviation safety, maintain electricity transfer arrangements, data protection, defence policy, policing, and approaches to security and environmental policy.
A further £114m will be needed for EU agencies whose functions will need to be repatriated to their UK counterparts.
The European Banking Authority is one such organisation, whose functions are likely to be picked up by the Prudential Regulation Authority.
Mr Cassels said: "The major administrative challenge of repatriating the functions of EU agencies to their UK counterparts, while minimising disruption for regulated individuals and entities, represents one of the most challenging aspects of the Brexit process."
George McLellan, a lawyer in the firm's regulatory group said: "To minimise disruption that may be caused in the transition process, businesses which are regulated by EU and UK agencies will need to ensure that they monitor who their regulators are and what EU regulation will continue to apply to them for UK-purposes post-Brexit.”