Single parent - Single Person Child Carer Credit

Has anyone any experience of this. A vexatious claim was made to social welfare in relation to child benefit to a relation of mine. This person is recently divorced and one child in full time education is residing solely with them. While we were formulating the response to social welfare this tax credit SPCCC came to light, something neither of us were aware of. It gives two benefits.

a) Tax credit worth €1750 (worth €33 a week)
b) Reduced tax band of 4K 20% instead of 40%

We believe then you can claim it for 4 tax years. So 2023, 2022, 2021 and 2020 if the child was solely resident with one parent. So can claim it in the current 2023 tax returns or do you have to redo prior years.

What relevance does a divorce decree make if the date of separation is say 28th Feb in 2021 but you were effectively separated in 2020.

I'm assuming 2021 with 10 months is what you would calculate? For just 2021.

And if we are correct, the other spouse is also entitled to it as 2nd child resides solely with them (in full time education). It's especially valuable if you're a higher rate tax payer.

I can't speak to the part about the vexatious claim but everything else is right. You can go back 4 years to 2020, regardless of when divorce decree was (presuming that they were separated in 2020). And yes if there is a second child under 18 or over 18 staying with the other parent and in full time education the other parent is also entitled to the benefits. And the tax band at 20% is increased (you mention reduced but looks like a typo).