What is the name of your state (only U.S. law)? We are in NC and me and my soon to be ex have been seperated for 4 years. She left and verbally told me I could have the house as long as she could get what she wanted out of the house. I let her have what she wanted and have not gotten it in writing, which I know is stupid, and now I've been paying the mortgage for 4 years on my own and she's decided she wants me to pay her for her part of when she lived here. Does she have rights?
(To begin this is more of an issue involving North Carolina domestic law than one of real property.)
"Does she have rights?"
If the home was acquired by either of you during the course of the marriage and not with the separate assets of one or the other, then the home is marital property in which you both have "rights"! And presumptively "equal rights'.
However, unless you two can reach a formal, acknowledged written agreement as to how those rights are to be fairly parceled out, they won't be except by a North Carolina family court sitting on a divorce case. And then by the court ordering an equitable division of the home first taking into account other marital assets and the factors set forth by statute, which are quite numerous. (See: North Carolina General Statutes Section 50-20)
In the mean time, neither has any obligation to pay the other any thing.
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What should be of greater concern to you is your potential financial risks in allowing this failed marriage to drag. For as long as the marriage continues and because of North Carolina's "doctrine of necessaries" you could be found to be financially responsible for her necessaries, including medical care.
And even though there is an exception to that doctrine called the "separation exception" you could still be put to the expensive burden of defending any lawsuits by her providers. North Carolina case law is replete with such instances.
Its long past the time when you should be sitting down with your lawyer.