Chapter 4.16 RCW (Limitation of actions) contain the statutes regarding time limits on civil cases.
Figuring out which statute applies and whether the time has passed are sometimes complex.
Moreover, you likely signed some sort of contract with the creditor. The contract may provide for applying the laws of some other state or extending the time limits.
If the debt is for a significant amount of money, you may find it cost effective to review your facts and options with an attorney.