Revolut has an EU banking license issued by Lithuania [0] but only offers accounts covered by the guarantee in Lithuania [1]. If you are resident elsewhere, you are not protected.
You should think of Revolut and Transferwise as being more like PayPal than a bank.
[0]: https://blog.revolut.com/we-got-a-banking-licence/
[1]: https://blog.revolut.com/revolut-bank-launches-in-lithuania/
Not sure why, but since customer acquisition doesn't seem to be limited by it, it's probably not their top priority.
You are protected up to £85k per bank.
Revolut Ltd (FRN:900562)
...
None of your money is protected by FSCS
And of course, on further inspection, Revolut does _not_ have a UK banking licence.
I had wrongly assumed this, given they were advertising their banking services on the London Underground for months (back when I was taking the tube to work).
https://www.bbc.co.uk/news/business-47168860
https://www.thetimes.co.uk/article/nikolay-storonskys-revolu....
https://www.fscs.org.uk/check-your-money-is-protected/
Type in revolut.
The money is ring fenced usually in a too big to fail bank.
Edit:
Though they have a banking licence in Lithuania and may be insured there?