Should taxes be added to the home inspection quotes ?

That is up to your state.

I believe most states don’t charge sales tax for inspections. I know I don’t pay it in Kansas. Check with your CPA though.

No. I know of no state where you charge taxes on professional services.

Washington State (not DC). No state income tax. All labor is taxed at POS. (Yes, there are always exceptions). I lived in SW WA from 1988 thru 2006. I founded my inspection business there in 1996. Relocated to MN near end of 2006.

We do in Canada. We have to charge a Goods and Services Tax.