Businesses with nexus in Idaho are required to register with the Idaho State Tax Commission and to charge, collect, and remit the appropriate tax.

Generally, a business has nexus in Idaho when it has a physical presence there, such as a retail store, warehouse, inventory, or the regular presence of traveling salespeople or representatives. However, out-of-state sellers can also establish nexus in the ways described below.

An out-of-state business may establish nexus in Idaho by engaging in the recurring solicitation of purchases from residents of Idaho, or otherwise purposefully directing business activities at residents.

If your business has ties to businesses in Idaho, including affiliates, it may have nexus. A retailer has substantial nexus with Idaho when all the following conditions are met:

• The retailer and an in-state business maintaining one or more locations in Idaho are related parties.

• The retailer and the in-state business use an identical or substantially similar name, trade name, trademark or goodwill to develop, promote or maintain sales, or the in-state business provides services to, or that inure to the benefit of, the out-of-state business related to developing, promoting or maintaining the in-state market.

• The out-of-state retailer had sales in Idaho of at least $100,000 during the previous year.
  
  Idaho Statutes 63-3615A and Chapter 36, and the Idaho State Tax Commission: Business and Sales/Use Taxes; Online, Catalog, and Out-of-State Shopping.