Self Assessment and interest

Hi i have a full time normal job and did a one of job last year for 20k as a side hustle Im doing my self assessment and i have a tax bill for the 23/24. However its predicting i'll get this again this tax year. So have to pay half of next years tax bill plus the 23/24 tax bill. then the second half in july. I will do no more side hustle work this year. Can i get the two predicted tax bills taken off? If i do get them taken off and i end up doing work (very very very unlikely). I will get a tax bill for 24/25 next year in 25/26, Will i have to pay interest as i kinda delayed the payment?

Hi Amy R,
If you do not expect your earning as much in 24/25, you can reduce your payments on account down accordingly.
You can do this on your Personal Tax Account, or contact us by webchat or phone here for more advice
Self Assessment: general enquiries
If, after reducing your payments on account, you find that you do earn more than you expected, you may be charged interest.
Contact us as above to increase your payments on account again.
More information can be found here:
Understand your Self Assessment tax bill
Thank you. 

Ok make sense! Thank you!