Childcare Code

I can't get a childcare code as HMRC cannot find my husbands details of self assessment. Tax return 2022-2023 was completed and received on 23rd October 2023 and we have a submission receipt reference. When we applied three months ago all was confirmed but when we reapplied they couldn't find his details. We have spent August settling our daughter into childcare but will probably have to withdraw her from September as we have no code for the 15 hours. HMRC suggested we resubmit his tax returns 2022-2023 but was told this would result in a fine as they would be deemed late. This is not a problem from the Childcare department but the Self Assessment but whoever we talk to has not helped and we are no further advanced. Any help/advice would be appreciated.

So HMRC confirmed today that our self assessment returns for 2022-23 are all present and correct on line so after being on hold for 1.5 hours to Childcare department they still can't see the details so can not give a code. Not sure where to go next. Any help would be much appreciated.