Who do they think they are?
In the past we have had cause to complain about the behaviour of HMRC's debt management and banking department (DMB), whose job it is to collect unpaid tax. Aggressive letters and calls to taxpayers are not uncommon, and collectors may refuse to deal with your tax agent even where a signed authority is in place with HMRC.
HMRC has responded by improving the communication between the tax offices and the debt collectors. Now the debt collectors should have up-to-date tax debt figures, so should not be chasing tax which is not due or has already been paid.
HMRC are no longer using bailiffs employed by third parties to physically collect tax debts. If someone turns up on your doorstep demanding payment of tax, you can ring 0300 200 3862 to check whether he is a genuine HMRC employee. Also call us without delay.