what is the statute of limitations for collecting on an overdue debt in CA

Neither. The statute of limitations runs from the date of last activity which is usually either the date of last payment or the date of the last charge. You can read more at my blog http://www.californaidebtblog.com which also discusses this and provides the Statute of LImitations for many states.

The California statutes of limitations start to run when you have defaulted on an obligation, not when you have incurred that obligation. Whether or not the debt has become "uncollectible" is, to me, not the relevant question. If you defaulted on a loan payment and since have not cured the default, the date of the default starts the running of the staute of limitations.

Both, it seems they collection agencies try to collect whenever, I have agency that claims i owe a couple of debts that are about 14 years old from the original time payment was stopped, I thought it was only 7 years, then they take it off and it appears from another debt collector. Or if there is a charge off and they three years later somebody buys it off and they stick on your credit report, just like that.

How long can a debt be collected for? I thought it was 7 years in CA.Can they start the 7 years all over everytime a new debt collector buys it from another or from the original creditor

what is the statue of limitation for credit card debt?