Michigan Contractors and Sales Tax Obligations

Michigan's sales tax framework treats contractors differently from retailers, and the distinction creates compliance obligations that affect every construction project in the state. Contractors who purchase materials, perform installation work, or operate across both real property and tangible personal property categories must understand where the Michigan Department of Treasury draws the line between taxable and non-taxable transactions. Misclassification of materials or services is among the most common audit findings for contractors operating under Michigan's General Sales Tax Act (MCL 205.51 et seq.).

Definition and scope

Under Michigan law, contractors are generally classified as consumers of materials, not retailers. This means a contractor typically pays sales tax at the point of purchase on materials that will be permanently affixed to real property, rather than collecting sales tax from the property owner at project completion. The Michigan Department of Treasury formalizes this classification in Revenue Administrative Bulletin 2016-18, which governs the treatment of construction contracts.

The scope of this framework covers:

• Real property contracts: New construction, remodeling, renovation, and repair work that results in permanent improvements to land or buildings
• Tangible personal property: Equipment, fixtures, or items that remain personal property after installation and are not permanently affixed
• Mixed contracts: Transactions involving both real property components and personal property components billed under a single contract

Work covered under Michigan's sales tax rules applies to all licensed and unlicensed contractors performing taxable work within state boundaries. For a broader overview of the contractor licensing framework, the Michigan Contractor Services reference covers the regulatory structure governing who operates in this market.

How it works

The operational mechanism turns on whether materials become part of real property upon installation. Materials affixed to real property are taxed at the purchase stage — the contractor pays 6% Michigan sales tax (MCL 205.52) to the supplier, and the contractor's invoice to the property owner does not itemize or collect sales tax separately.

For tangible personal property that does not become part of real property — such as freestanding equipment, production machinery, or movable trade fixtures — the contractor acts as a retailer. In this role, the contractor collects sales tax from the customer at 6% and remits it to the Michigan Department of Treasury.

The critical classification steps are:

1. Determine the nature of the item: Does the item lose its identity as personal property upon installation? Does removing it damage the building structure?
2. Identify the contract type: Is this a lump-sum contract, a cost-plus contract, or a time-and-materials billing?
3. Assess exemption eligibility: Is the purchaser a qualified exempt entity (e.g., a nonprofit, government body, or industrial processor)?
4. Apply the correct tax role: Consumer (pay tax on purchase) or retailer (collect tax from customer)?
5. Document the transaction: Retain purchase invoices, exemption certificates, and contract documents for a minimum of 4 years, consistent with standard Michigan audit exposure windows.

Michigan contractors engaged in commercial contractor requirements work should pay particular attention to the industrial processing exemption under MCL 205.54t, which can significantly alter the tax treatment of materials installed in manufacturing facilities.

Common scenarios

Residential remodeling: A Michigan residential builder installs new kitchen cabinets and countertops. The materials are permanently affixed and become part of the real property. The builder pays sales tax to the lumber yard and kitchen supplier, and does not charge the homeowner sales tax on materials. The homeowner pays only the contract price. For licensing standards applicable to this contractor type, see Michigan Residential Builder License.

HVAC equipment installation: An HVAC contractor installs a central air conditioning system that is bolted to the structure and connected to ductwork. Under Michigan Department of Treasury guidance, this is treated as real property. The contractor pays tax at purchase. If instead the contractor installs a freestanding portable unit that remains personal property, the contractor collects and remits tax from the customer. See Michigan HVAC Contractor Requirements for the licensing context.

Government and nonprofit contracts: When a contractor performs work for a qualifying exempt entity — a public school, a municipality, or a qualifying religious organization — materials purchased for that contract may qualify for a sales tax exemption. The contractor must obtain a completed Michigan Sales Tax Exemption Certificate (Form 3372) from the exempt entity before purchasing materials tax-free.

Subcontractor relationships: A subcontractor purchasing materials for a project managed by a general contractor bears the same consumer-of-materials obligation. The sub pays tax at purchase regardless of who holds the prime contract. The Michigan General Contractor vs. Subcontractor classification distinctions are relevant here because tax liability does not shift automatically based on contract hierarchy.

Decision boundaries

The line between the contractor-as-consumer and contractor-as-retailer roles determines who remits tax and when. The Michigan Department of Treasury does not permit contractors to shift this liability through contract language alone.

Contractors performing electrical work should review Michigan Electrical Contractor Requirements alongside these tax obligations, as installations involving service panels and permanently wired systems consistently fall under the real-property consumer classification.

Scope limitations: This page covers Michigan state sales tax obligations only. Federal tax obligations, Michigan use tax (which mirrors sales tax at 6% under MCL 205.93), income tax treatment of contract revenues, and multi-state apportionment questions are not covered here. Contractors operating across state lines must consult the tax authority of each state where work is performed. Local municipal taxes, where applicable, are also outside the scope of this reference.

References

• Michigan General Sales Tax Act (MCL 205.51 et seq.) — Michigan Legislature
• Michigan Use Tax Act (MCL 205.93) — Michigan Legislature
• Revenue Administrative Bulletin 2016-18 — Michigan Department of Treasury
• Michigan Sales Tax Exemption Certificate (Form 3372) — Michigan Department of Treasury
• MCL 205.54t — Industrial Processing Exemption — Michigan Legislature
• Michigan Department of Treasury — Business Taxes