US Student loan repayment question

I just got married in the UK and now reside in the UK with my English husband. The time has come for me to re-certify my federal student loans on an IDR plan and I am really stumped. Because my income has changed since my last tax return (filed as single as I was not married during the previous working year), I need to fill out the "alternative document" form. This requires me to enter my spouse's SSN and tax return info etc but he obviously doesn't have either. Right now I am not working and I live in the UK, and he is a non-resident alien for US tax purposes.

What information do I need to provide the loan servicer? A cover letter explaining the situation? If I need to show proof of his income, what form should that take? Or should I just select the option to base my student loan payments for this year on last year's tax return, even though I'm not working anymore? They won't ask questions if I do that, but I may end up paying more per month.

Before you provide that information to your loan servicer:

If you file your taxes as “married filing jointly,” your total household income will be counted as available for repayment of student loans and you may not be eligible for some income-driven student loan repayment plans. Check the fine-print on your current plan.

If you file your US taxes as "married filing separately" there may be plans that would reduce your expected monthly payment to minimal or zero dollars per month. (Except for the RePaye program, which looks at all household income regardless of how you file your taxes.)  You would not report your husband's income, as I understand it.

If  you think one of the other available plans would be better than the one you are on now, you can request to switch to it.  Be really sure of what repayment program you are on/request and the rules that pertain to it.

The following links may be of use -

https://studentaid.ed.gov/sa/repay-loans/understand/plans/income-driven

https://thecollegeinvestor.com/17807/the-math-behind-married-filing-separately-for-ibr-or-paye/

If all the above is old news to you, and you are going to report as "married" rather than "married filing separately", I would suggest contacting the loan servicing provider to ask what they want.

Best of luck with it!