Unmarried parent Tax Credit

Can anybody help with my situation?
I am living with my partner with 3 young kids, legally I am not entitled to claim single parent tax credit? My partner is a stay at home Mum with no income at all (except monthly child benefit). Is there anything I can claim for Tax wise, Thanks

No you're not entitled to claim the tax credit.

You may be entitled to family income supplement if your income is within certain limits.