Sending in HS227 for offset of loss against PAYE - post or email?

Hi there, As the title says, I need to fill in an HS227 (2024) for an offset of self-employment loss against PAYE tax in the same tax year. I can't do this in my 2023-24 tax return as I have used cash basis for expenses reporting. Please can I ask how do I submit the HS227? This isn't explicity mentioned in the guidance. Can I send it to HMRC via email, or do I need to post it? I can't find an email address or a postal address online. Many thanks! Rebecca

Hi 
Sideways loss relief is not permitted when you use the cash basis of accounting.
You can only carry the loss forward and use it againt a profit from the same trade in a future tax year.
Please have a look at the guidance at:
Cash basis
Thank you.