HS304 vs DT Form

I am trying to understand the difference between these. Is it simply that the HS304 is completed annually along with your tax return (and attached) to claim back the tax deduction. Whereas, the DT form is completed once, like a Non Resident Landlord form. Also does the DT Form need to be redone if the claimed amount changes.

Hi,
For non UK resident individuals, the DT individual form is submitted to the overseas tax authority and is validated by them. We can then use the validated form to authorise live pension providers to stop deducting tax in the current tax year and future tax years. Where an individual needs to complete a self assessment tax return to claim tax relief for a tax year, then they submit the form HS304 along with their tax return. This allows the processing of tax relief for the tax year that has already ended, so that HMRC can refund the overpaid tax.
Thank you

Thank you for the clarification, although you didn't answer whether the DT form needs to be redone if the claimed amount changes?

Hi,
A new DT form is required if there are any changes and/or a new source of income.
Thank you