Electrical sub-panel for garage

House has detached garage and could not locate sub-panel inside or outside of garage. Garage has two garage door openers and two outlets in garage. Main panel on exterior of house was not labeled. To my understanding if only one circuit is going to the garage, a sub-panel is not required. Is that correct? If so, the next step is to figure out if there is only one circuit going to the garage and since the main panel is not labeled I’d have to trip each breaker and go back and forth to the garage to see if all the power is off after tripping each breaker. Is that correct?

Yes, typically.

Report that the Service is not labeled and recommend that it be labeled for safety.

Larry’s got it. Not for us to trip breakers.

Typical HI does not require one to diagnose the issue. If the main is not labelled, I’d just defer to an electrician to label and verify circuitry for the garage as well as others.

Good wording, Simon.