Paying self assessment tax bill through my tax code

I filed my tax return for tax year 2024 on 22 November 2024. I owe about £1,500 of tax. My account shows I owe this amount by 31 January 2025. My PAYE tax code for 24-25 has been changed in the HMRC system to reflect professional subscriptions and BIKs from my employer, however I am unable to view my tax code for 25-26. I understand from https://www.gov.uk/pay-self-assessment-tax-bill/through-your-tax-code that I should be able to pay this £1,500 of tax through my PAYE code being updated. As I owe less than £3,000; I already pay tax through PAYE; and I have submitted an online return by 30 December. However, my tax code for 24-25 doesn't factor in the underpayment (I wouldn't expect it to) but the 25-26 tax code is not visible. How do I know that HMRC will collect this through my tax code being adjusted - I don't want to run the risk of late payment interest if I don't make a bank transfer by 31 January 2025.

Hi, To check that the balance is going to be collected in your 2025/26 tax code we will need to access your record. You can contact HMRC at:
Self Assessment: general enquiries
Thank you.