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Short answer: In New Jersey, a business that buys medical or laboratory supplies to resell gives its supplier Form ST-3, the Sales Tax Resale Certificate, instead of paying sales tax on that purchase. The buyer must hold a New Jersey Certificate of Authority, and the seller must have a fully completed certificate on file. Supplies the buyer consumes itself do not qualify. This is general tax-form information, not tax advice.
The generic rules for resale certificates are covered in resale certificates for medical supply distributors and resale certificate vs seller’s permit. This page covers only what the New Jersey Division of Taxation says about Form ST-3 and applies it, clearly labelled, to a medical or lab supply business.
What Form ST-3 is
Form ST-3 (revision 3-23) is titled “Sales Tax Resale Certificate” and carries two boxes: Single-Purchase Certificate and Blanket Certificate. The Division states that a seller must collect sales tax on taxable property or services unless the purchaser gives a fully completed exemption certificate. The form is not mailed to the Division; the purchaser gives it to the seller. Per the form, it may be reproduced. Tax Topic Bulletin S&U-6 (Rev. 6/24) describes ST-3 as the certificate registered sellers use to buy tangible personal property or services for resale in its present form or for incorporation into other property held for sale.
Who can issue it
On the form, the purchaser certifies that it holds a valid Certificate of Authority to collect New Jersey Sales and Use Tax. The Division also states that a seller must be registered to accept an exemption certificate. The signer is an authorized person such as an owner, partner or corporate officer, signing under penalties for perjury and false swearing.
Resale inventory vs own-use purchases
The form’s reasons for exemption are: purchase for resale in its present form, resale as converted into or a component part of a product, use in performing a taxable service on personal property, and purchase of services for those purposes. The Division’s own examples draw the line between stock and everything else:
- Proper: a retail appliance store buying appliances for resale; a furniture maker buying lumber; a service station buying parts used in repairs.
- Improper: a distributor buying cleaning supplies or materials for its own office maintenance, “even though it is in the business of distributing such supplies”; a retailer buying office equipment for its own use.
- S&U-6 adds that a toy store may buy dolls for resale with a certificate but must pay tax on display cases, and that items taken out of inventory for personal use are subject to New Jersey Use Tax.
Illustrative reading for a medical or lab supply business
The table below applies those examples by analogy. It is our reading of the Division’s rules, not a Division statement about medical supplies; each row is tied to the Division example named in the middle column.
| Purchase by the business | Division’s rule it follows | Likely ST-3 treatment |
|---|---|---|
| Supplies bought as stock to sell on in their present form | Inventory intended for resale, rent or lease (S&U-6) | Resale certificate applies |
| Cleaning supplies for the business’s own premises | Distributor’s own office-maintenance supplies are improper, even if it distributes such supplies (ST-3) | Pay tax; certificate does not apply |
| Office equipment and shelving or display fixtures | Office equipment for own use; display cases (ST-3, S&U-6) | Pay tax; certificate does not apply |
| Stock later pulled for the owner’s own use | Items taken from inventory for personal use (S&U-6) | Business pays Use Tax on those items |
What a fully completed certificate contains
Under the form’s instructions, a certificate is fully completed when it has the purchaser’s name and address, New Jersey taxpayer identification number, type of business, reason or reasons for exemption, and a signature if on paper (including by fax). The seller’s name and address are not required. The purchaser also states what it is principally engaged in selling and describes the property purchased.
Seller acceptance, 90-day, 120-day and retention rules
The table below turns the Division’s rules into a checklist, one column for each side of the sale.
| Rule | Buyer (issues ST-3) | Seller (accepts ST-3) |
|---|---|---|
| Registration | Hold a valid New Jersey Certificate of Authority | Be registered to accept an exemption certificate |
| Completeness | Complete every required field and sign | Collect tax unless the certificate is fully completed |
| Timing | If an exemption is claimed improperly, the purchaser is liable | Relief from liability if a fully completed certificate is received within 90 days of the date of sale |
| Audit | Be ready to supply a complete certificate | At least 120 days after the Division’s request to obtain a complete certificate taken in good faith, or other information showing the sale was not taxable |
| Retention | Keep your own copies | Keep for four years from the date of the last sale the certificate covers; certificates must be contemporaneously dated and summary records are not adequate evidence |
S&U-6 states records must be kept for not less than four years. The form notes that where data is entered electronically the paper certificate need not be kept.
Blanket vs single-purchase certificates
A blanket certificate covers additional purchases of the same general type by the same purchaser, where there is a recurring relationship, defined as no more than 12 months elapsing between sales transactions. The blanket box is checked, and each later invoice or sales slip must be marked with the purchaser’s name, address and identification number. The Division may not require renewal while the relationship recurs, but recommends sellers obtain updated certificates every four years.
Out-of-state buyers
S&U-6 says a supplier may accept another state’s resale certificate from an out-of-state retailer. Other routes it names are the Multistate Tax Commission Uniform Sales & Use Tax Certificate (Multijurisdiction), Form ST-3NR and the Streamlined Sales Tax certificate (ST-SST). The bulletin describes ST-SST as usable in most circumstances in place of general-use certificates, and New Jersey is a Streamlined Sales Tax member state.
Common misunderstandings
- “Being a distributor makes everything exempt.” The Division’s example says otherwise: cleaning supplies for a distributor’s own office are taxable even though it distributes them.
- “A contractor can use ST-3 for materials.” A contractor cannot issue ST-3 for materials and supplies; the form points to other forms (ST-13 and UZ-4).
- “One certificate lasts forever.” A blanket certificate depends on sales continuing at intervals of no more than 12 months, and the Division recommends refreshing it every four years.
- “The seller is always protected.” Relief applies only to a fully completed certificate received within 90 days of the sale.
FAQ
What is a New Jersey resale certificate?
It is Form ST-3, the Sales Tax Resale Certificate, which a registered New Jersey purchaser gives a seller to buy goods or services for resale without paying sales tax on that purchase.
Do I mail Form ST-3 to the state?
No. The form states it is not mailed to the Division of Taxation; it goes to the seller.
How long must a supplier keep it?
Four years from the date of the last sale the certificate covers.
Can I use it for supplies my own clinic or lab consumes?
The Division’s examples treat a business’s own-use purchases as outside the resale exemption, so such purchases are generally taxed. Confirm specific cases with the Division of Taxation.
Sources
- New Jersey Division of Taxation, Form ST-3 Sales Tax Resale Certificate (3-23) and instructions, https://www.nj.gov/treasury/taxation/pdf/other_forms/sales/st3.pdf, checked 2026-11-01.
- New Jersey Division of Taxation, Tax Topic Bulletin S&U-6, Sales Tax Exemption Administration (Rev. 6/24), https://www.nj.gov/treasury/taxation/pdf/pubs/sales/su6.pdf, checked 2026-11-01.
Related reading: medical supply wholesalers, how to get a wholesale license, laboratory supply wholesale pricing.
