British citizens who look to move to the European Union before the transition period ends need to begin planning their financial affairs as the countdown begins, advisers have warned.

The UK government has one more week before the 30 June deadline in which to seek an extension to the Brexit transition period, set to end on 31 December.

The government has shown no indication it plans to do so, however.

UK nationals who are settled in an EU state before the end of the year can lock in a lifetime of citizen’s rights under the withdrawal deal.

There are signs many are looking to do this. In May, proper...