Why does some of my outlets have 2 breakers tied into them?

What type of outlets, regular wall outlets? And what size breakers are they tied to?

Regular wall outlets on 15A breakers

How do you know they're tied to 2 breakers? If they were on 2 different breakers on the same phase you'd still get 120v, but if they were on different phases you'd be getting 240v. Either way you can't do it. What makes you say they are on multiple breakers...

I'm doing construction on my house and I thought I had the breaker off to two of the outlets but they weren't according to my contractor. The panel indicated that one breaker was for the exterior plug so I switched it off and tested one of the plugs and it was off. As my contractor broke through the drywall the outlet had the pwr in and pwr back out and he thought pwr was off but it wasn't as he accidentally arched it and two breakers tripped. This was dido on the other outlet to.

Sounds like the outlets he hit were fed from another circuit. As for the 2 breakers going off, they may have had a common neutral causing both breakers to trip.

What do you mean by outlets being fed from another circuit?

It sounds like the outlet you thought was on the circuit you shut off, was actually on a different circuit. If you shut off the breaker, and checked an outlet, and that had no power, then the live outlet was on another circuit. The only other way that that might happen is if the outlet you checked was outside, and had triped a GFCI, and the outlet that was still live was 'upstream' of the GFCI. But that's an unlikely set of events. I think you just chose the wrong breaker. Typically the outside outlet would be on a different circuit than the interior outlets.

Put an outlet back on the wire he cut that was live .Make sure you have no live wires uncapped. Plug a lamp in. turn the breaker back on. Shut off breakers one at a time until the light goes off. Then you'll know what circuit that outlet is on.

How many wires are in the cable the contractor cut? If there are three wires and a ground (black, red, white and bare) this is probably two circuits sharing a neutral. Breakers should be (and now are required by code to be) tied together.


P.S.
You cannot rely on the markings on the panel to be complete information about a circuit. The electrician would have to wire a book if he had to describe all of the outlets that were on each circuit.