"It is excellent to see official recognition given to the City of Gibraltar, a huge accolade to its rich history and dynamism," British Prime Minister Boris Johnson said in a statement.
The final agreement for Gibraltar should be ready within six months.
Agreement has been reached "without prejudice to the inalienable claims" to sovereignty.
After a post-Brexit transition period ends in December, Britain may get some direct access to EU financial markets under the bloc's 'equivalence' system.
It looks like Gibraltar could be in for a rocky ride post Brexit but they have a plan.
Iranian Grace I supertanker detained.
Gibraltarians are British citizens and rejected by 99% to 1% the idea of the UK sharing sovereignty with Spain in a vote in 2002 and in a previous referendum in 1967.