A Michigan sales tax audit is an examination by the Michigan Department of Treasury to check whether your business correctly reported and paid tax. The auditor may review your returns, sales records, accounting data, and support for transactions treated as exempt or otherwise not taxable. If Treasury identifies a difference, it may issue a preliminary audit determination and later a formal assessment.
Michigan applies one statewide sales tax rate and has no local sales tax, so sellers do not have to calculate separate city or county sales tax rates. That does not remove the need to establish whether a transaction is taxable, properly sourced to Michigan, and supported by records. Sales Tax Compliance USA is a people-led, done-for-you service for ecommerce and cross-border sellers. We can help organize the audit response, review the records and proposed adjustments, and support you through the process.
What to expect in a Michigan sales tax audit
The Michigan Department of Treasury will identify the audit and the periods or records it wants to examine. The auditor may ask questions, request documents, and compare your sales and accounting records with the returns you filed. Treasury can examine books and records to determine whether the correct tax was reported and paid.
An audit may involve detailed review of transactions or sampling. Treasury’s audit sampling materials describe separating Michigan destination sales into groups such as taxed and non-taxed transactions. If the auditor proposes adjustments, ask which transactions, assumptions, and records support each change. Keep a written record of requests, responses, and discussions.
What to do when you receive an audit notice
Read the notice carefully and note the auditor’s contact details, the periods under review, the requested records, and any response date. Confirm that the notice relates to your business and preserve relevant accounting, order, payment, shipping, and tax records. Do not ignore the request or send an incomplete explanation without first understanding what Treasury is asking.
Contact the auditor promptly if you need clarification or more time, and keep copies of everything you provide. Avoid changing or recreating source records; instead, explain any gaps and provide reliable supporting material. If the notice includes a proposed determination or assessment, treat its stated response and appeal dates as urgent and verify the applicable procedure with Treasury or a qualified adviser.
Records Michigan auditors may request
Treasury may request records needed for a fair and impartial audit. Examples listed in its audit materials include federal and Michigan tax returns, sales tax returns and supporting worksheets, accounting workpapers, monthly profit-and-loss statements, sales journals, bank statements, cancelled checks, and check registers. For an ecommerce seller, relevant supporting records may also include order-level transaction data, invoices, payment processor reports, shipping or delivery evidence, and customer exemption documentation.
For sales treated as exempt, organize the evidence that supports the treatment, such as exemption certificates and transaction details. Treasury’s published guidance on recordkeeping identifies information that may be required for an exemption claim, including the purchaser, sale date, item, exemption type, and sale amount; resale claims may also require the purchaser’s sales tax license or use tax registration number. The exact request depends on the audit, so ask the auditor to clarify the scope rather than assuming a particular list is exhaustive.
How far back can a Michigan sales tax audit go?
Treasury says the general limitation period for taxes it administers is four years, and an audit normally covers the most recent four-year period. Michigan law generally bars assessment of a deficiency after four years from the later of the date the return was due or the date it was filed. The period can be extended in circumstances provided by law, including a written agreement to extend it.
A return that was not filed can change the analysis: Treasury states that tax may be assessed for a period for which no return was filed. The applicable period can also depend on extensions and the specific returns and issues involved. Check the periods listed in your notice and ask Treasury or an adviser to confirm the limitation position for your facts before relying on a general rule.
Common issues that can trigger audit adjustments
Adjustments can arise when reported sales do not reconcile with accounting records, payment reports, or other transaction data; when a seller treats a sale as exempt without adequate support; or when tax was not accrued on a transaction Treasury considers taxable. Missing records can make it harder to substantiate reported figures or exemption claims. For cross-border and multichannel sellers, differences between order, payment, shipping, and accounting data deserve particular attention.
Michigan’s single statewide rate and lack of local sales taxes simplify rate calculations, but they do not resolve whether a sale is taxable or whether it belongs in the Michigan sales population. Review the transaction facts and documentation behind each proposed adjustment. Do not assume that a platform report, a customer’s location, or an exemption label alone proves the correct tax treatment.
Proposed assessments, interest, and penalties
A Preliminary Audit Determination (PAD) identifies Treasury’s proposed tax, penalty, and interest, and may show an amount due or refund. It is a stage to review the findings and provide relevant information; it is not the same as a final assessment. Treasury’s audit materials describe a process for requesting reconsideration of a PAD when you want to provide additional audit documents.
Check the calculation line by line: the transactions included, the tax treatment applied, and the interest or penalty amounts. If you disagree, identify the specific items and provide records or a clear explanation. The amount and basis of interest or penalties depend on the assessment and applicable rules; review the notice and confirm any disputed calculation with Treasury or a tax professional.
How to challenge a Michigan sales tax assessment
Start by distinguishing a PAD from a final assessment or other appealable Treasury decision. For a PAD, Treasury’s materials direct taxpayers seeking to submit additional audit documents to use the Request for Reconsideration of a Preliminary Audit Determination, Form 5244. Follow the instructions and response date on the PAD, and explain which findings you dispute and why.
For a final assessment, Michigan law provides an appeal to the Michigan Tax Tribunal within 60 days or to the Michigan Court of Claims within 90 days after the assessment, decision, or order. The uncontested portion generally must be paid as a prerequisite to appeal. These are consequential deadlines and procedural requirements; verify the current instructions and the date that applies to your notice before filing. A missed deadline can affect your ability to challenge the determination.
Michigan Treasury appeal options and deadlines
During the audit process, respond to the auditor by the date stated in the audit correspondence. If Treasury issues a PAD, use the reconsideration process described in the notice and Treasury’s Form 5244 instructions when seeking review or submitting additional audit documents. If the matter proceeds to an intent to assess, Treasury’s taxpayer-rights materials describe requesting an informal conference in writing within 60 days of the date on the notice.
After a final assessment or qualifying final decision, the statutory routes include the Michigan Tax Tribunal, generally within 60 days, or the Court of Claims, generally within 90 days. The uncontested amount must generally be paid before appeal. Because the correct route and deadline depend on the document you received and the posture of the case, use the notice and current Treasury instructions to confirm the exact deadline. Do not treat a PAD response date as interchangeable with a final-assessment appeal deadline.
How our team handles your audit from start to finish
Sales Tax Compliance USA is a done-for-you service staffed by people, not a software product. We begin by reviewing the notice, identifying the periods and issues under examination, and helping you assemble the records Treasury requested. We can organize transaction data and supporting documents so the auditor can trace reported sales and the evidence behind tax treatments.
We then help review proposed adjustments, identify gaps or inconsistencies, and prepare a clear response supported by records. If Treasury issues a PAD or assessment, we can help you understand the stated findings and coordinate next steps, including identifying when a tax attorney or other specialist should be involved. The scope of support depends on your circumstances, and we do not promise a particular audit outcome.
When to get professional help with an audit
Consider getting help as soon as you receive a notice if records are incomplete, the audit covers multiple sales channels or countries, the proposed adjustment is material to your business, or you are unsure how to support exempt sales. Professional review is also useful when Treasury’s calculations do not match your records or when a PAD, intent to assess, or final assessment arrives with a response deadline.
You do not automatically need a tax attorney for every audit. A sales tax compliance professional can help organize records and explain operational tax issues; an attorney may be appropriate for legal disputes, formal appeals, or advice about litigation and legal rights. If you are uncertain which kind of help fits, share the notice and circumstances with a qualified professional promptly, and confirm procedural requirements with the Michigan Department of Treasury.
Michigan sales tax audit review: how common transaction categories differ and what evidence to gather
| Transaction category | Audit question and useful supporting records |
|---|---|
| Sale reported as taxable | Does the reported sale reconcile to the order, invoice, payment, and sales records? Gather transaction-level sales data, sales journals, and accounting workpapers. |
| Sale treated as exempt or non-taxable | What supports the claimed treatment? Gather the transaction details and applicable exemption documentation, including purchaser and sale information. |
| Resale or lease exemption claim | Does the file support the resale or lease basis? Gather the purchaser’s exemption documentation and, where applicable, sales tax license or use tax registration information. |
| Michigan destination sale | Was the transaction included in the Michigan sales population and treated consistently? Gather shipping or delivery evidence and order records. |
| Sales totals that differ across systems | Can the difference between returns, accounting, and payment records be explained? Gather monthly reconciliations, processor reports, bank records, and workpapers. |
Frequently asked questions
What happens during a Michigan sales tax audit?
The Michigan Department of Treasury reviews records and information to determine whether your business correctly reported and paid tax. The auditor may request returns, accounting records, sales documentation, and support for exempt transactions, then propose adjustments if the records indicate a difference. Treasury may issue a Preliminary Audit Determination before a final assessment.
Not sure how this applies to your business? We handle US sales tax registration, filing and remittance for ecommerce sellers as a fully managed service, for one fee. Book a free consultation and we will review your own position with you.
What records can Michigan auditors request?
Treasury may request records necessary for a fair and impartial audit, including tax returns, sales tax worksheets, accounting workpapers, profit-and-loss statements, sales journals, bank statements, cancelled checks, and check registers. For ecommerce transactions, order, payment, shipping, invoice, and exemption records may also help substantiate the reported treatment. The precise request depends on the audit.
How far back can a Michigan sales tax audit go?
Treasury says audits normally cover the most recent four-year period, and Michigan law generally limits assessment to four years after the later of the return’s due date or filing date. The period may be extended in circumstances allowed by law, and Treasury states that tax may be assessed for a period when no return was filed. Confirm the periods and any extension issues for your specific notice.
What should I do if I receive a Michigan sales tax audit notice?
Read the notice, note the periods, requested records, contact information, and response date, then preserve relevant records and respond promptly. Ask the auditor to clarify anything unclear and keep copies of all submissions and communications. If the notice includes a proposed determination or assessment, verify the applicable response or appeal deadline immediately.
Can I challenge a Michigan sales tax audit assessment?
Yes. The available process depends on whether you have a Preliminary Audit Determination, an intent to assess, or a final assessment. Treasury provides a reconsideration process for a PAD, while Michigan law provides appeal routes for qualifying final assessments and decisions. Follow the instructions and deadlines on the document you received.
How do I appeal a Michigan Treasury audit determination?
For a PAD, Treasury’s materials identify Form 5244 as the request for reconsideration when you want to provide additional audit documents. For a final assessment or qualifying decision, Michigan law generally allows an appeal to the Michigan Tax Tribunal within 60 days or the Court of Claims within 90 days, with the uncontested portion generally payable before appeal. Confirm the correct route and deadline from your notice and current Treasury instructions.
What happens if I disagree with a preliminary audit determination?
Review the proposed adjustments and identify the specific transactions or calculations you dispute. Treasury’s audit materials direct taxpayers seeking to provide additional audit documents to request reconsideration using Form 5244 and to follow the PAD’s response instructions. If the dispute continues into a later notice or final assessment, separate appeal deadlines and procedures may apply.
Do I need a tax attorney for a Michigan sales tax audit?
Not necessarily. A sales tax compliance professional can help organize records, reconcile transactions, and respond to operational audit questions, while a tax attorney may be appropriate for legal disputes, formal appeals, or litigation. If the proposed liability is significant or a formal appeal deadline is approaching, seek qualified advice promptly.
How we handle this for you
The mechanics in Michigan are manageable on their own; the cost is the time it takes every single filing period, in every state you are registered in. We are a managed service: our team registers you with the Michigan Department of Treasury, prepares and files your returns, and keeps you compliant period after period. You get one point of contact and one invoice — you do not get another dashboard to learn.
See our sales tax compliance services, check where you have obligations with the nexus calculator, or talk to us about Michigan.
Official sources
- https://www.michigan.gov/taxes/-/media/Project/Websites/treasury/Forms/TCB/2315.pdf?rev=18b78189dd4e4b91b060cff2bc833158
- https://www.michigan.gov/taxes/-/media/Project/Websites/treasury/Forms/TCB/4870.pdf?rev=e391afce8ac14ccb9ab57a755c9dc191
- https://www.michigan.gov/taxes/coll-audit/audit
- https://www.legislature.mi.gov/Laws/MCL?objectName=mcl-205-21
- https://www.legislature.mi.gov/documents/mcl/pdf/mcl-chap205.pdf
- https://www.michigan.gov/taxes/rep-legal/rab/2021-revenue-administrative-bulletin-2021-18
Reviewed by Paul le Roux, CA(SA). Sales Tax Compliance USA handles US sales tax registration, filing and remittance for cross-border and domestic ecommerce sellers as a fully managed service.
This page is general information for educational purposes and does not constitute legal or tax advice. Sales tax rules change and depend on your specific facts. Consult a qualified tax professional about your own position.
Related guides
Other Michigan guides: Amazon FBA · Back sales tax · Economic nexus · Filing · Foreign sellers · Marketplace facilitator
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