A state-by-state guide to exemption certificates

Dawn Moser Dawn Moser May 8, 2025

This blog post has been updated. It was originally published in February 2023.

We’ve talked about sales tax exemptions many times on this blog. The big caveat is always the same: Each state has its own rules. Figuring out sales tax exemption certificates can be particularly daunting.

To that end, here’s a primer on sales tax exemption certificates. You can also just jump directly to our state-by-state guide to certificate requirements.

What is a sales tax exemption certificate?

A sales tax exemption certificate is a document that allows a business, organization, or individual to purchase normally taxable goods or services tax free.

Purchasers apply for exemption certificates and provide them to sellers at checkout. In the case of a blanket certificate, it’s not necessary to use a new certificate for each purchase, as long as the qualifying factors are the same and the certificate is valid.

Sellers are required to collect and validate certificates prior to exempting tax. If a certificate is incomplete, expired, or unavailable, the seller is responsible for collecting tax and the purchaser can later request a refund from the state. 

Sellers store each certificate, so it’s accessible for future purchases or to validate the exemption if the business is audited. 

What’s the difference between an exemption certificate and a resale certificate?

  • An exemption certificate is a document that allows tax-exempt purchases based on the status or circumstances of the purchaser. 
  • A resale certificate is a document that allows a business to make tax-exempt purchases based on the assumption the goods will be resold and the sales tax will be paid by the end consumer.

Some states use the same document for both exemption and resale certificates. Others have different documents for each.

Who can use a sales tax exemption certificate?

Getting a sales tax exemption sounds like a pretty sweet deal, but alas, it’s not an option for everyone. Exempt entities vary for each state, but often include:

  • Nonprofit organizations
  • Religious or educational affiliations
  • Federal, state, and local government
  • Specific industries
  • Manufacturers

Do states use the same exemption certificates for all exempt purchases?

No. Most states have certificates for specific types of exemptions. And collecting the wrong certificate for an exemption is often the same as having no certificate: The seller can be liable for the uncollected taxes. 

Some states, like California and Kentucky, have different certificates for each type of exemption, including specific industries. This can also be true for different types of nonprofit organizations, as is the case in Colorado and Maine, to name a couple.

How long do you need to keep exemption certificates on file?

Exemption certificates are worth every penny of exempted tax and possibly more. If you’re audited and can’t produce a certificate to justify an exempt sale, you may be responsible for the applicable taxes, as well as potential penalties.

States have their own statutes of limitations for sales tax audits. Certificates from exempt purchases should be kept for at least the time frame for which you could be assessed. 

There are also variations on when certificates expire. Some certificates never expire, some are only good for a year. Even if there’s no official expiration, it’s good to verify the information is up to date every couple of years or so. Changes to a business, such as name, address, and ownership, can void an exemption certificate.

Can exempt sales establish nexus?

Sales tax nexus is a relationship between a business and a state that creates an obligation for the business to register to collect tax and file returns in a given state. All states with a general sales tax (plus Alaska, Puerto Rico, and Washington, D.C.) have economic nexus conditions based on a business’s amount of sales and/or number of transactions. 

Each state has its own rules concerning whether exempt sales count toward economic nexus totals. So even if you aren’t required to collect taxes, you may still be required to register and file returns in a state.

If you do establish nexus, you’ll need to either collect sales tax or a valid exemption certificate on any normally taxable sales. Otherwise, you could be held liable for the uncollected tax.

Many states exempt certain products from sales tax, such as food for home consumption in Washington or diapers and feminine hygiene products in Colorado. In these kinds of cases, you do not need to collect a certificate to exempt tax on each sale.

How can I get information for my state?

We worked with Sales Tax Institute to create a State-by-State Exemption Certificate Guide to help you identify which certificates are required for your state. In it, you’ll also find information on how often you should renew your documentation and links to the forms you need.  
 
States may change acceptance policies for their certificates without notifying the Multistate Tax Commission (MTC). Check with the state to determine current policy. 
 
Streamlined Sales Tax (SST) note: Not all states allow all exemptions listed on the SST Exemption Certificate, but a business doesn’t need to be registered through the SST Registration System to use the Streamlined Exemption Certificate. 
 
Expiration periods vary by state and exemption certificate, and most states have different certificates for different situations or entities. Check with your state to get the most up-to-date information.  
 

Please consult a sales tax expert who can discuss your specific requirements. And consider exploring how automating exemption certificate management can help you streamline tax compliance.

Expiration period

  • Renew annually

This state takes multijurisdictional tax forms  

Reference

Alaska doesn’t have a state sales tax, but local sales tax is permitted and is in effect in multiple jurisdictions.

Sales tax exemptions are also determined by individual municipalities.

Expiration period

  • Valid until the end of each calendar year

This state takes multijurisdictional tax forms 
 
Reference

Expiration period

  • 4 years from the due date or filing date, whichever is later
  • 6 years if more than 25% of the taxable base is omitted
  • No expiration period if a return is not filed, or if a fraudulent return is filed with intent to evade taxes

 This state takes multijurisdictional tax forms

Reference

Expiration period

  • No stated expiration period

This state takes multijurisdictional tax forms 

This state participates in streamlined sales tax 

Reference

Expiration period

  • Valid until revoked in writing by the issuer unless issued for a specific transaction

 This state takes multijurisdictional tax forms

Reference

Expiration period

  • Valid until cancelled by the Department of Revenue in writing or revoked by the city or state

 This state takes multijurisdictional tax forms 
 
Reference

Expiration period

  • 3 years

Reference

Delaware doesn’t have a state sales tax, or similar. Therefore, an exemption certificate is not applicable.

Expiration period

  • 5 years

 This state takes multijurisdictional tax forms

Reference

Expiration period

  • Valid until revoked in writing

This state takes multijurisdictional tax forms  

This state participates in streamlined sales tax

Reference

Expiration period

  • Does not expire

 This state takes multijurisdictional tax forms

Reference

Expiration period

  • No stated expiration period

 This state takes multijurisdictional tax forms

Reference

Expiration period

  • Validity period varies depending on purchaser

Reference

Expiration period

  • Does not expire

 This state participates in streamlined sales tax

Reference

Expiration period

  • 3 years

This state takes multijurisdictional tax forms 

This state participates in streamlined sales tax 
 
Reference

Expiration period

  • Blanket certificate remains valid provided purchaser is making recurring purchases. Tax-exempt entity exemption certificates have an expiration period.

This state takes multijurisdictional tax forms  
This state participates in streamlined sales tax

Reference

Expiration period

  • 4 years

This state takes multijurisdictional tax forms 

This state participates in streamlined sales tax

Reference

Expiration period

ReferenceSales tax forms

Expiration period

  • No stated expiration period

 This state takes multijurisdictional tax forms 
Reference

Expiration period

  • 5 years

Reference

Expiration period

  • No stated expiration period

Reference

Expiration period

  • 4 years

This state takes multijurisdictional tax forms 

This state participates in streamlined sales tax 
 
Reference

Expiration period

  • Does not expire unless information changes; should be updated every 3–5 years 

This state takes multijurisdictional tax forms 

This state participates in streamlined sales tax 

 
Reference

Expiration period

  • No stated expiration date

Reference

Expiration period

  • 5 years

 This state takes multijurisdictional tax forms 
 
Reference

Montana doesn’t have a state sales tax, or similar. Therefore, an exemption certificate is not applicable.

Expiration period

  • Valid indefinitely 

This state takes multijurisdictional tax forms 

This state participates in streamlined sales tax 
 
Reference

Expiration period

  • 5 years

 This state participates in streamlined sales tax 
 
Reference

New Hampshire doesn’t have a state sales tax, or similar. Therefore, an exemption certificate is not applicable.

Expiration period

  • No stated expiration period

This state takes multijurisdictional tax forms

This state participates in streamlined sales tax

Reference

Expiration period

  • No stated expiration period

 This state takes multijurisdictional tax forms

Reference

Expiration period

  • No stated expiration period

Reference

Expiration period

  • Blanket certificate remains valid provided purchaser is making recurring purchases

 This state takes multijurisdictional tax forms 

This state participates in streamlined sales tax

Reference

Expiration period

  • No stated expiration period

 This state takes multijurisdictional tax forms 

 This state participates in streamlined sales tax

Reference

Expiration period

  • No stated expiration period

 This state participates in streamlined sales tax

Reference

Expiration period

  • Blanket certificate remains valid provided purchaser is making recurring purchases

 This state takes multijurisdictional tax forms 

 This state participates in streamlined sales tax

Reference

Oregon doesn’t have a state sales tax, or similar. Therefore, an exemption certificate is not applicable.

Expiration period

  • No stated expiration period 

 This state takes multijurisdictional tax forms

Reference

Expiration period

  • 3 years

Reference

Expiration period

  • Blanket certificate remains valid provided purchaser is making recurring purchases

This state takes multijurisdictional tax forms 

This state participates in streamlined sales tax

Reference

Expiration period

  • No stated expiration period

 This state takes multijurisdictional tax forms

Reference

Expiration period

  • Blanket certificate remains valid until cancelled by the purchaser

 This state takes multijurisdictional tax forms 

This state participates in streamlined sales tax  

Reference

Expiration period

  • Blanket certificate remains valid provided purchaser is making recurring purchases 

 This state takes multijurisdictional tax forms 

 This state participates in streamlined sales tax

Reference

Expiration period

  • No stated expiration period

 This state takes multijurisdictional tax forms

Reference

Expiration period

  • Certificate remains valid provided purchaser is making recurring purchases

 This state takes multijurisdictional tax forms  

This state participates in streamlined sales tax

Reference

Expiration period

  • Valid indefinitely when used as a blanket certificate; otherwise, valid for single purchase

 This state takes multijurisdictional tax forms 

 This state participates in streamlined sales tax

Reference

Expiration period

  • Valid until notice from Department of Taxation that certificate is no longer acceptable

Reference

Expiration period

  • Blanket certificate remains valid provided purchaser is making recurring purchases

 This state takes multijurisdictional tax forms 

 This state participates in streamlined sales tax

Reference

Expiration period

  • Blanket certificate remains valid provided purchaser is making recurring purchases

Reference

Expiration period

  • Blanket certificate remains valid provided purchaser is making recurring purchases

 This state takes multijurisdictional tax forms 

 This state participates in streamlined sales tax

Reference

Expiration period

  • Valid indefinitely, but should be reviewed periodically

 This state takes multijurisdictional tax forms 

 This state participates in streamlined sales tax

Reference

Expiration period

  • No stated expiration period

 This state takes multijurisdictional tax forms 

 This state participates in streamlined sales tax

Reference

Managing exemption certificates for your business

Whether you’re making exempt purchases or managing documents from exempt customers, it’s important to supply or collect valid exemption certificates. Not doing so can create liability with state auditors. 

If you’re buying or selling in more than a couple of states, keeping track of which forms are required for which sales and when they expire is challenging. 

Automating certificate management can go a long way toward peace of mind and reduced risk. 

  • Avalara Exemption Certificate Management can help businesses large or small with collecting, validating, storing, and accessing exemption and resale certificates.
  • Avalara Vendor Exemption Management can help you obtain and supply the right documents to support your exemption requests.
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United States Exempt Sales Sales and Use Tax
Sales tax rates, rules, and regulations change frequently. Although we hope you'll find this information helpful, this blog is for informational purposes only and does not provide legal or tax advice.
Dawn Moser
Dawn Moser Content Writer
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