If my partner owns the house (not spouse, only in his name) but I paid for half the mortgage/DP/Closing, do I claim to own our home or do I “rent”

[ColeenD3]

You own the home if you are on the deed. If you are not, you can't claim property taxes. If you are not on the mortgage, you can't claim a deduction for the interest.

This does not make you a renter, you just share the space and probably help pay expenses. There is no landlord/tenant relationship.