I've just received an email purporting to be from HMRC, advising me that I am due a refund.
I'm pretty sure this is phoney. It states that the claim for this refund must be made by filling an online form and gives a link.
Do NOT open this link if you receive the same!! It's possibly a 'phishing' scam, after your personal and financial details, or it could carry all sorts of malware and potentially destroy you computer.
I'm sure this is a fake, as HMRC don't have my email address.