Why the MTC form doesn’t work for California by default

If you’ve ever handed a customer the MTC Uniform Sales & Use Tax Certificate — Multijurisdiction form and been told “we can’t accept this for California,” you’re running into one of the most common snags in multi-state resale-certificate compliance.

Short version: California’s Board of Equalization (now part of the CDTFA) explicitly rejects the MTC form for California-sourced resale transactions. The state requires its own form, CDTFA-230 (formerly BOE-230), or a compliant equivalent that includes the exact language from California’s Revenue and Taxation Code §6091.

Why California is stricter than most

California’s resale-certificate rule (Regulation 1668) spells out specific content that must appear on any document used to claim a resale exemption:

1. The name and address of the purchaser.
2. The purchaser’s California seller’s permit number, OR a statement that the purchaser is not required to hold a California permit + the reason.
3. A description of the property being purchased.
4. A statement that the property is being purchased for resale.
5. A signature and the date.

The MTC form covers most of those points generically, but it was designed as a multi-state compromise — it doesn’t use California’s exact statutory language, and it doesn’t require the purchaser to certify they hold a California seller’s permit. That’s the showstopper.

What you can accept instead

If you have nexus in California and you’re selling to a California wholesale buyer, ask for one of:

• CDTFA-230 (General Resale Certificate) — the CDTFA’s own form.
• CDTFA-230-A (Resale Certificate — Sales by Auto Auctions).
• A custom certificate your buyer supplies, provided it contains all six items from Regulation 1668 above.

Keep the signed copy on file for at least four years (CDTFA’s audit lookback window — see our state-by-state retention guide).

What ResaleProof does

• Generates a compliant CDTFA-230 automatically when a customer selects California in the portal.
• Validates the California seller’s permit number format before accepting the cert.
• Applies the US_CA_RESELLER_EXEMPTION tax-exemption flag on Shopify so tax is skipped at checkout.

If a buyer insists on using the MTC form for a California transaction, politely point them at this article — the rejection isn’t your policy, it’s California’s.

Related

• How long should you keep resale certificates?
• How to verify a resale certificate is valid
• Single-purchase vs blanket resale certificates

Sources

• CDTFA Regulation 1668, “Sales for Resale” — cdtfa.ca.gov
• MTC Uniform Sales & Use Tax Certificate — Multijurisdiction, §1(d) California footnote — mtc.gov

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