How much AC is too much.

Has anyone had any issues with high AC levels at home? I am receiving 123 to 126 volts at my home at times. What level is too much and could cause damage to equipment?

I heard that a lot of the power companies are no longer regulating the outside grid like they use to do. To save money they are not regulating the voltage level at some of the transformers. If you live near a transformer that is not regulated you could have issues.

Any recommendations on the best way to correct incomming voltage ... Variac , AC regenerator (PS Audio) ?
I have the same issues here, with similar voltage. It is not a problem with modern gear, but if it goes up and down during the day like mine, it may throw your bias off a bit on your tube amps if they are manual bias units. I would not suggest using a variac if it is a problem. Most cause sonic degradation or current limiting. Regenerators would be a better answer. It was only an issue for me when I was using a 40 year old tube amp that was designed for 115 volts or below.
I have the same problem, voltage shooting up to 130 on occasion. To correct it I purchased an APC battery back-up unit. You can set the voltage parameters so that if the incoming voltage exceeds the limits (up or down) it will sound an alarm and go to battery back-up. Hasn't failed me yet.
Looking at the bias level LEDs on my tube amp tells the story...they are all over the place at different times of day and I try to ignore them...I've checked these with a meter and clearly the neighborhood has juice issues. The amp seems to handle it fine.
The North American electrical standard is +_5% (114V-126V). This should only present a problem with older tube gear.