HMRC has released an update regarding some additional tax that certain customers are required to pay. The authority responded to an enquiry by breaking down the figures to clarify how tax bills are calculated. A customer got in touch with the authority regarding a message they had received. They said: "Please explain why my tax code has altered you say I owe £847 but you want to reduce my allowance by £4,235 and you will take £70 a month. Why has the tax code not been reduced by £847? This just