Many states (Idaho among them) don't charge sales tax on cleaning services. Others tax all of it, or only some items, like upholstery cleaning or fabric protector. Set a rule for each state you work in and estimates add the right tax for you.
Set up a state
Settings → Sales Tax (owners and admins; also on the office web page under Settings).
Add a State.
Tax rate — 0% if the state doesn't tax your services.
What's taxable: Tax every service, or turn that off and pick the services that are taxable (each floor service and add-on from your rate sets, Upholstery, and Other items for typed-in lines). Stairs follow their surface.
Tax travel and Tax extra charges if your state taxes those.
Save.
A state that isn't listed charges no tax.
On an estimate
The estimate reads the state from the customer's address (…, Boise, ID 83702) and uses that state's rule. The Sales Tax section shows the rate and the tax; the proposal prints a Sales tax (6.5%) line above the total.
Change the rate for one job, or turn on Tax-exempt. Use [state]'s Rule puts it back.
A sent proposal keeps the tax it went out with, even if you change the settings later. Drafts follow the settings.
A service minimum line is taxed for the taxable share of the job.
Multi-location proposals tax each location by its own state.
Tax-exempt customers
On the customer (Edit Customer → Tax-exempt), for schools, churches, government buildings and others with an exemption certificate. Their estimates charge no tax and the proposal says Tax-exempt.
QuickBooks
Tax goes to QuickBooks as its own Sales tax line. If you use QuickBooks' automated sales tax, check the first few invoices.