First it depends how you want to hook up your stairlift. Some stairlifts can be installed with a simple power cord that plugs right into a nearby electrical outlet. This is obviously the easiest way.
Other stairlifts need to be set up on a dedicated circuit and hard-wired into the electrical wires inside your walls.
Obviously this can add expense to your installation.
In some states, such as Washington, state law requires that all stairlifts be hard-wired on their own circuit.
If this is the case for you, you’ll need to get an appropriate electrical permit and have a qualified electrician come and do the work before your stairlift installers arrive.
And although the added cost won’t be welcome, there are advantages to direct-wired lifts. First off, you don’t have yet another electrical cord lying on the ground presenting a tripping hazard. Secondly, there’s no risk that the cord will come out of the wall and leave the chair in an uncharged state, which could be a safety and/or convenience hazard.
Check with a local stairlift installer about whether an electrical permit is required in your area.