u/SnooSprouts6342

For the third year in a row I've been hit with a surprise tax bill due to underpayment. I pay my tax through PAYE through my employer, but every year for the past three years it's been several grand under what it should be and I end up with a large unexpected (though now less unexpected) bill to pay at the end of the year.

Is there any way to get either my employer or HMRC to align with the tax that I actually should be paying? I haven't changed salary, job, or benefits over the past few years, so I'm not sure what's throwing the calculation off. Any guidance would be appreciated...