Blog
Practical guidance on resale and exemption certificates for wholesale sellers — what makes one valid, and what goes wrong in an audit.
How to verify a New York resale certificate (ST-120)
Verify a New York ST-120: what the January 2026 revision changed, Part 1 or Part 2, the sales tax ID and the state's vendor lookup, the 90-day rule, and three years from the return.
Read more →How to verify a New Jersey resale certificate (ST-3)
Verify a New Jersey ST-3: the five things that make it fully completed, the 90-day rule and the 120-day cure, what the state's lookup tools actually prove, and when you need an ST-3NR instead.
Read more →How to verify a Pennsylvania resale certificate (REV-1220)
Verify a Pennsylvania REV-1220: the eight reason boxes and which one is resale, the 60-day possession rule, the state's public license list, and the four-year retention rule.
Read more →South Carolina will accept another state's resale certificate number
South Carolina takes another state's resale number on its own form. Louisiana accepts nothing but its own. Acceptance rules are fifty independent decisions.
Read more →How to verify a California resale certificate
Verify a California resale certificate (CDTFA-230): the Regulation 1668 elements, CDTFA's permit lookup, and why a certificate that never expires shifts risk onto you
Read more →8 ways a resale certificate fails (and why the state bills you, not your buyer)
Eight failure modes auditors actually find -- wrong form, lapsed registration, expired certificates, and the valid certificate that still doesn't count.
Read more →What surprised me building a certificate validator
I did months of discovery before building a resale certificate validator and still got surprised: how routine audits are, ID formats no state publishes, and verification that happens over the phone.
Read more →How to verify a South Carolina resale certificate
Verify a South Carolina resale certificate (Form ST-8A) in minutes: both required pages, the MyDORWAY license lookup, and why the certificate itself never expires
Read more →Louisiana rejects the MTC form
Louisiana does not accept the multi-state certificate. They only accept Form R-1064, issued directly to registered dealers.
Read more →How to verify a Louisiana resale certificate
Verify a Louisiana resale certificate (Form R-1064) in minutes: the LaTAP lookup's four inputs, annual expirations, and why the MTC form won't work
Read more →Is an EIN enough? EIN vs. resale certificate
An EIN identifies a business to the IRS. It does not exempt a sale from sales tax — only a valid resale certificate does. Here's the difference, and why it matters in an audit.
Read more →How to verify a resale certificate is valid
Having a PDF on file is not the audit test. Here are the six checks an auditor actually applies to a resale certificate — and the moment to run them.
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