Experian | Ask Max | Bankruptcy law changes did not affect credit reporting
The 7 year period for BK 13 is voluntary on the part of the CRA's. Kinda like extortion to get people to pay something back in order to have better credit sooner. Blows the whole "pay for delete is illegal" idea right out of the water.
So the answer is 10 years, but you get a gift if you complete the CH 13. If you dismissed and it came off in 7 years anyway, then you got a bonus prize.