Have you has a tax demand that’s startled / shocked / disturbed you – and HMRC are asking for it all by Jan 31?
CALL THEM if payment’s not going to be practicable for you. One of the worst sins I’ve found from their point of view is not letting them know what’s going on. They’ll still demand the money, no question about that! But don’t put the brown envelope in a drawer and hope they’ll forget you. They WON’T, and when they do eventually reconnect with you, they’ll charge you for Denial.
My other recommendation is that ANY payment is better than NO payment. If you can part-pay your bill, do that as soon as you can, then contact them to discuss plans for the balance.
And if you think it’s all wrong anyway? Check in with your accountant – or contact me if you need one! I confess I may not now have time to check everything through for you and get back to HMRC in time for the January 31 payment deadline. But we can certainly check the past returns ASAP, and look at a strategy for future.