A "statute of limitations" refers to how long a party has to bring suit in court. Chapter 16 of the Texas Civil Practice and Remedies Code sets out limitation periods for various civil causes of actions, and section 16.004 of the Code sets out a 4-year limitations period for suits related to debt. According to the statute, a lawsuit must be brought "not later than four years after the day the cause of action accrues." The Texas Attorney General provides the following information about the limitations period [PDF]:
We also receive inquiries regarding the obligation to pay old debts. If you never paid off an old debt, that does not mean it is not valid; you are obligated to pay it even if it has been several years since you were contacted by a collection agency or the business you owe the debt to.
Many consumers are under the impression that after a certain number of years, they are no longer responsible for an unpaid debt.
Under Chapter 16.004 of the Texas Civil Practice & Remedies Code, Four-Year Limitations Period, the statute of limitations for filing suit to collect a debt is no later than four years after the cause of action accrues. An example of when the cause of action accrues is the date on which the debt is declared to be in default.
If you are unsure of when the 4-year period begins and ends, it would be best to consult with an attorney who could help calculate when your cause of action accrued. Keep in mind that certain actions may "reset the clock" or re-age the 4-year period — e.g., making a partial payment, agreeing to a payment plan, affirming the debt. For more information about debt collection, review this debt collection article from the Texas Attorney General. The library also has a research guide if you'd like more information about debt collection laws.