Personal Tax Code error, what to do next?

Hello, 2 years ago I was sole trader. From that time period, I have some money I chose to pay with my tax code since I stopped being a sole trader and started working for a company back on March 2022. My tax code has been around 800 for the time being until now, no surprises or anything. On October, my previous company went bust and I joined a new one. Same salary. I was unemployed for 1 week. On November 27th I got a notification that my tax code had been updated. I did not check it back then because I thought it would be a new one for the new year. Today I received my payslip and to my surprise I found my new tax code had a K in it, and it took a much bigger chunk of my salary than before. This month I receive my yearly bonus, and due to the tax issue, it is 100% gone. I checked in gov.uk and saw that it claimed I owed a huge amount in taxes. I called and, after an hour in hold, got in touch with an agent that very kindly explained it was an issue and corrected my tax code back to how it was before. However, my company already issued the payslip and they mentioned they can't correct it until HMRC sends them the new tax code, which will take 10 days or more, most likely. My question is, in this case, what should I do or what can I expect? Will I be refunded that money? Should I call again tomorrow? Any help would be appreciated. Thanks

Hi,

I'm sorry to hear about the issues regarding your tax code. Codes are issued to your employer overnight, and are usually received within 2-3 working days. If your employer receives this code in time to apply it before they run their next payroll, you should receive a refund of any overpaid tax in your very next wage. If the new code is received after payroll has been calculated, the code update will usually be applied in the following payroll calculation, with your repayment being paid in the wage after that.

Thank you.