I worked for an agency from 09/2022 - 12/2022. I started a new job via a direct employer (so independent of the agency) in 01/2023. I forgot to make sure that the agency had taken me off their employee records, so even though I wasn't receiving any money from the agency, HMRC had me down as being employed a 2 different jobs. Therefore, on my first paycheck from my new employer (started in 01/2023), my tax code was BR.
I called HMRC about this, then called the agency and got them to generate P45 and send it to HMRC: they did this and everything was sorted out so that on my next paycheck I was on the 1257L tax code again. I also received a tax code notice from HMRC telling me that my tax code is 1257L (received this letter roughly in 02/2023).
However, in my paycheck from the first month of the new financial year (04/2023) my tax code is BR and I have consequently been charged way too much tax.
I have set up a government gateway account however this is not particularly helpful because all I can do is see what tax code I am on, I can't change it or inform anyone that it is wrong.
The government gateway/personal tax account shows that my tax free allowance is 12570, and it shows the correct current employer, correct date that I started working for them and it also correctly shows the agency as a past employer, not as a current one. However, when I click on another tab it shows that my tax free income of £12570 is for the agency - my past employer - and not my current employer.
I have of course tried phoning but after taking up my time asking me to go through security questions, the IVR says that you 'are too busy to take my call, please try calling another time' and then hangs up on me without ever putting me into a queue to wait for a person to speak to me. This has happened on 2 different days now, on one day I called just 30 minutes after the line opened.