Intentional incompetence
Unfortunately, there is hardly anything one can do when overtaxed. This 3.6 Bn overtax is not a mistake, because HMRC usually overestimates an individual's income and is under no obligation to pay it back unless you spend a huge amount of time and get an accountant to help you. Their tax code letters are vague and difficult to understand!!!
Why do they estimate and create all these problems instead of waiting until the end of the year, then tax you accordingly? This is obviously good for the government, so most probably intentional.
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