So you have been separated for years. You have your own bank accounts. You bought your own house. You bought your own car. You have retirement and investment accounts. Maybe you even separated everything when you each started living apart, but guess what, if you did not get divorced ALL of that is still community property in Texas. That means it is all subject to division by the Court.
Yes you can put on evidence to the Court that you have lived separate lives for 5, 10 even 15 years, however, long it is, but the Judge still has the duty to make a just and right division of community property. So if one of you has had significant growth in assets and the other has not fared as well the Judge could divide up your assets giving some to your long-time separated spouse.
I have had clients seeking to only modify their child custody orders and learn that they were still married living apart. Luckily in those cases there were not a lot of assets and I advised them that the cost to get a divorce would not be much greater than modifying the child custody orders since both parties were in agreement on getting a divorce. But there are cases where an agreement would not be reached which could be a costly legal battle.
Further, if you are still married and you or your spouse are seriously injured your spouse still has a right to make decisions for your health and care. Further, if you were to pass away, your spouse is entitled to a share of the community property that you have amassed. So even if you have a will giving your property to anyone other than your spouse, your spouse is still entitled to his/her share of the community property and the remainder goes to those designated in your will.
This has come up a lot in the same-sex marriage context as well because couples could get married in other states, but they could not get divorced here. These couples may have been separated for years, but now that same-sex marriage must be recognized in all states, these couples now need to get a divorce to properly divide their community estate.
So while it seems like you are already divorced because you have been living separate lives for so long, under Texas law your spouse still has rights and is still entitled to a share of the community property. If this is you, you either need to file for divorce yourself or contact an attorney to help you file for divorce so that you can protect your property and your rights.