An Arkansas contractor taking work in North Dakota deals with the same four questions everywhere: who licenses the trade, when a licence is actually required, when workers compensation kicks in, and where the business registers. Below is North Dakota's answer to each, with the agency's own link.
Licensing
North Dakota Secretary of State
Contractor license required when a job exceeds $4,000, issued by the Secretary of State through the FirstStop portal. Classes by contract size: D up to $100,000, C up to $300,000, B up to $500,000, A over $500,000. Liability insurance and WSI verification required.
https://www.sos.nd.gov/business/licensing-registration/contractors
Workers compensation
North Dakota Workforce Safety & Insurance (WSI)
Monopolistic state fund: WSI is the sole workers' compensation provider and administrator; every ND employer, including prospective employers, must carry WSI coverage for employees.
Tax registration
North Dakota Office of State Tax Commissioner
Contractors pay sales and use tax on materials as final users; repair labor is not taxable.
New hire reporting
Most states require newly hired employees to be reported within a short window of their start date.
https://www.hhs.nd.gov/childsupport/employers/new-hire-reporting
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Starting or running the business itself is covered in the contractor business guide. Arkansas licence records for Benton and Washington counties are in the contractor directory.