Duplication of tax bill across Simple Assessment and Self Assessment

Probably one for HMRC Admin? I moved from self-employed to PAYE during 22_23, contacted HMRC and they agreed they'd withdraw the notice to file a Self Assessment for 22_23. That triggered a new Simple Assessment with associated tax bill as I had underpaid that year. I needed to pay this bill direct - couldn't pay it via PAYE because we did this switch after the Dec '23 deadline. That was fine. Deadline for new Simple Assessment tax bill was 1 May 2024. All good. BUT... now I've started getting a separate, identical tax bills under Self Assessment, retrospectively dated to be paid by January 2024, with accruing interest. I quickly paid off the Simple Assessment one, but am still getting increasing bills. Have written twice to HMRC - no confirmation of receipt or reply. Tried calling but not been able to get through... How do I sort this out - this bill is getting bigger by the minute? And watchout anyone else switching from SELF ASSESSMENT to PAYE - be very sure of your tax calculations so you don't get billed twice too.

Hi

It could be that we need some additional information to fully close your Self Assessment record.
To allow us to do fully review and close your record, contact us by webchat or post via Self Assessment: general enquiries 

Thank you

Thank you. I have written three letters with no replies or acknowledgements, so no longer have faith that post is a useful option. Today sadly, I got a brand new letter from HMRC called a Simple Assessment Tax Calculation with new figures of £0.00 recorded against my 2022_2023 income tax. I have no idea why this has been sent or what it means or how HMRC has got it so wrong. I did earn some money, which is why I needed to pay some tax, which I paid. I can now find no record of my payments anywhere on my HMRC portal. I have a horrible feeling HMRC have closed my Simple Assessment BY MISTAKE instead of the self-assessment. I just need to speak to someone with the understanding to sort it all out. I will try webchat in the hope I can get through. HMRC Admin 5 - can you advise whether I should call the Self ASsessment line on 0300 200 3310 or the Simple Assessment line on 0300 322 7835 and if either, which typically has realistic times to get through?

I am unable to get through on webchat as just a computer. Any advice on contacting HMRC?

Hi  baerskimmason Mason,
Yes webchat would be an option or it would be the Self Assessment line 0300 200 3310.
If possible the best time to call would be when the lines open in the morning at 8am. Open 8am to 6pm Monday to Friday. 
Thank you. 

Hi baerskimmason Mason,
I am sorry you are unable to get through to webchat.
You can contact HMRC Self Assessment helpline here:
Self Assessment: general enquiries
Thank you.