In an expatriate forum call earlier this month, HMRC answered some questions with regards to legislation changes after Brexit and the ability for non-resident individuals to claim the personal allowance.
Currently, EU nationals are able to claim the UK personal allowance as a non-tax resident of the UK by virtue of their nationality. HMRC confirmed that it is their intention to continue to allow EU nationals to receive the personal allowance when the UK leaves the EU.
The Government also intends to pass legislation to ensure that non-resident UK nationals will also continue to receive the personal allowances post Brexit.
If you have any question with regards the above, please do reach out to your BDO contact.