Key takeaways
- Every registered quarter needs a filed Form ST-50, including a quarter with zero tax.
- The return for October to December 2026 is due January 20, 2027.
- A seller that meets the monthly tests pays by Monthly Voucher for a month whose tax is more than $500.
- Save the confirmation and a PDF of every guest filing on the day you file.
- Form ST-3 covers goods the buyer resells or incorporates into goods it sells, not tools, supplies or items the buyer uses.
Who files, how often and when it is due
A business registered to collect New Jersey sales tax files Form ST-50 for each calendar quarter. The Division's guidance says: "You must file a return for each quarter even if no tax is due and/or no sales were made during the period." A client with no sales still needs a filed zero-tax ST-50, so put every registered client on the quarterly calendar, including seasonal locations.
Returns and payments are due on or before 11:59 p.m. on the 20th day of the month after the filing period ends. If the 20th falls on a weekend or legal holiday, the due date moves to the following business day. The October to December 2026 ST-50 is due January 20, 2027, a Wednesday, so no weekend rule moves it. The July to September 2026 return was due October 20, 2026, so any copy still open is already late.
Set two dates for each client: the state due date, and an internal ledger close about five business days earlier. The close is the firm's own deadline, not a state rule.
Monthly vouchers for larger sellers
Quarterly filing is the base rule. The Division's filing-frequency page says some sellers must also make monthly payments, and it lists two tests: more than $30,000 of Sales and Use Tax collected in New Jersey during the prior calendar year, and more than $500 collected in the first and/or second month of the current calendar quarter. For 2026 payments, the first test looks at 2025 collections. Confirm a client's status on that page before its first voucher is due.
Worked example, with hypothetical figures at 6.625%. The client collected $41,000 of sales tax in 2025, so the prior-year test is met for 2026. October 2026 taxable sales of $12,000 produced $795.00 of tax. That is over $500, so a voucher is due November 20, 2026, applying the 20th-day rule to the monthly period. November taxable sales were $3,000, which produced $198.75 of tax. At $500 or less, no voucher is needed for that month. December is the third month and is not a voucher month, so its $629.38 of tax on $9,500 of taxable sales goes on the fourth-quarter ST-50 due January 20, 2027.
In the Tax Portal, choose "Form Type: Monthly Voucher" from the drop-down for each voucher. Before keying the quarter's ST-50, list every voucher already paid for that quarter, and confirm the quarter's tax is not paid twice.
Registered login or guest filing in the Tax Portal
The Tax Portal at taxportal.nj.gov offers "Create a New Profile" under New Tax Portal Users and "Returning Portal Users - Sign In" for existing users. Its Tax Services list includes "File a Tax Return as Guest", "Make a Payment as a Guest" and "Resume Filing Tax Return as Guest".
Decision rule. If the firm files for this client every quarter, file through the client's profile so history and confirmations sit in one place. If the firm is filing a single return, or the client has no profile, use the guest route, then save the record. The Division's pages I checked do not say how long a guest filing or its confirmation stays available, so the firm's copy is the record you rely on.
Save the confirmation page and a PDF of the submitted ST-50 to the client file the same day, and log the confirmation number. Keep portal logins in the firm's password manager, one login per client, not in the client folder.
Build the ST-50 from the sales ledger, not the bank deposits
Build the quarter from the point-of-sale or sales-order system. Deposits mix in tax collected, refunds, transfers and card-processing timing, so they do not give a clean taxable sales figure.
Tie taxable sales to tax collected. Example: taxable sales of $84,600 at 6.625% should produce $5,604.75 of tax. If the point-of-sale report shows $5,604.75 but the sales-tax liability account shows $5,560.00, the $44.75 gap goes to the client before filing, not after.
Pull resale and exempt sales as a separate list, with the certificate on file beside each sale.
Resale sales: what Form ST-3 covers
The Division's Tax Topic Bulletin S&U-6, Sales Tax Exemption Administration (Rev. 6/24), describes Form ST-3, the Resale Certificate. A registered seller uses it to buy tangible personal property or services for resale in their present form or for incorporation into property held for sale. The client keeps a completed form from each reseller it sold to without tax.
Match the certificate to the item. A toy store may give Form ST-3 for dolls it will sell, but not for display cases, because the cases are not intended for resale. A silversmith may use it for silver that becomes part of jewelry, but not for tools. Contractors' supplies and materials are not inventory for resale, and contractors use Form ST-13 for exempt purchases.
Decision rule. If the customer buys inventory it will resell or incorporate, ask for a Form ST-3. If the customer buys for its own use, ask for the exemption form that fits that purchase, or charge the tax. For a customer that buys regularly, a blanket certificate covers the recurring relationship, which exists when no more than 12 months pass between sales. The bulletin recommends updated blanket certificates every four years.
What makes a certificate usable and how long to keep it
A certificate is fully completed when it shows the purchaser's name and address, type of business, the reason for the exemption, and the purchaser's New Jersey tax identification number. Check each field before you accept it. The bulletin reproduces the form as revision (3-23), so use the current Form ST-3 from nj.gov.
Timing matters. Under the bulletin, a seller that accepts a fully completed certificate within 90 days after the date of sale is relieved of liability for the tax, even if the buyer improperly claimed the exemption. In an audit, the seller has at least 120 days after the Division's request for substantiation to obtain one. Get the certificate at the point of sale.
Retention. The bulletin says accepted certificates must be kept at least four years and must be contemporaneously dated. Summary records are not adequate evidence of a certificate's accuracy, so keep invoice-level detail too. If inventory bought with Form ST-3 is taken out for personal use, the business must pay New Jersey Use Tax on those items, so review the inventory log for personal withdrawals at year end.
Failure modes to check before you submit
Wrong period or form type. Quarterly tax goes on the ST-50 for the quarter, and monthly tax paid early goes through the Monthly Voucher form type. Keying a month as a quarter, or the reverse, leaves one period unpaid or paid twice.
Due date counted from the wrong month. The date is the 20th of the month after the quarter ends. The October to December 2026 ST-50 is due January 20, 2027, not December 20, 2026.
Missing certificate on a resale sale. Keep one folder per customer with the certificate, the invoice and a dated note, plus a missing-certificate log. Until a certificate is in the file, treat the sale as taxable unless the exemption can be documented.