Late penalty for a payment plan

I had a large SA for year ending 5th April 2022 which I couldn't afford to pay in one lump sum. I contacted HMRC as soon as I was made aware of the amount and I was placed on a payment plan for 12 months. I made the final payment on 22nd November 2023. This was agreed with HMRC and I paid the amount due each month on time with no late payments. I've now received a late payment charge which is completely unexpected as this tax bill was dealt with in agreement with HMRC. I've appealed but am still waiting on an answer and I just wondered if anyone knows what the potential outcome might be. Thanks

Hi leo1790,
You will need to contact HMRC to check on the appeal:
Self Assessment: general enquiries
Thank you. 

The same happened to me as well. I was told that as long as I pay the installments on time no penalties will be added and after a couple of months I got 700 pounds in late payment fees. How did it resolve for you? What did HMRC say?

Exactly the same here. £252 fine for making two late payments. I had an installment plan in place and never missed a payment or paid late. I eventually got through to someone, but they were unable to help, except for telling me the installments are an estimate, which can't be true, as I know how much I had to pay, which was divided into installments. I'm still waiting for a reply to my appeal.

Me too, Attempted to call HMRC today but could not get through to speak to someone. Soo stressful