If you owe more than £1,000 to HMRC the Summer Finance Bill will give HMRC the power to take it from your bank account!
According to an article on accounting web…
HMRC have said they will contact the taxpayer at least four times about the debt before commencing the DRD procedure. One of those occasions will be a face to face meeting with the taxpayer to establish that they have found the right debtor and calculated the debt correctly. This should avoid the situation where the HMRC letters have failed to arrive, or the taxpayer has not understood the liability.
There are penalties for banks who fail to comply with the notices issued by HMRC.