Joint Tax Assessment

You can claim the Home Carers tax credit for up to 4 years in the past. It says that in the last page of the Link posted.
So look into it.
You can ring Revenue too, you might have a bit of a wait on the phone, but hopefully you'll get someone who will explain what you need to do.
They are there to help people to claim what they are rightfully owed.
 
Hey, I notified Revenue last year that myself and my wife have been married since 2010 and elected to be jointly assessed for 2023. I also thought it would only apply going forward but was pleasantly surprised when they sent me a Statement of Liability for 2023, and updated SOL's for the three previous years with an extra refund in each year.
We were delighted to get all of these, and didn't even have to ask them to go back over previous years.