Thanks to @Revolutapp for this tax scam warning:
Scammers and fraudsters call you claiming to be HMRC. They offer you a rebate once you pay a fee, or by pretending you have to urgently pay a fine or you’ll be arrested.
To make it worse, these criminals can also change their phone numbers to make it look like you’re getting a genuine call from HMRC. They may even ask you to check the number online to validate it and build your trust.
HMRC will never contact you over the phone demanding payment at the risk of consequences or ask you to make a payment in return for a larger rebate afterwards.
If you’re contacted by someone claiming to be from HMRC or the Police, hang up and contact them independently via the contact numbers listed on www.gov.uk
UK Government banking account sort codes are 08-32-XX – If the payment you’re making isn’t to this Sort Code, it’s highly likely it’s a scam
HMRC and other tax authorities will never contact you over the phone demanding payment
HMRC and other tax authorities will never ask you to pay anyone else, like a solicitor or agent
HMRC and other tax authorities will never tell you which buttons to press or ask you to download software to allow someone else to view your screen or tell you to ignore payment warnings.