New Jersey treats capital improvements and repairs differently for sales tax purposes. The distinction determines whether you charge sales tax on your labor.

Capital improvements are projects that add value to a property or extend its useful life. A new roof, an addition, replacing all the windows, installing a new HVAC system, or building a garage all qualify. Labor for capital improvement work is exempt from New Jersey sales tax, but only if the property owner provides you with a completed Form ST-8, Certificate of Capital Improvement.

Repairs and maintenance work is taxable. Fixing a leak, patching a roof, servicing an HVAC unit, or replacing a single broken window counts as repair work. You need to charge sales tax on the labor portion of these jobs. The current rate is 6.625%.

Materials are taxable regardless of the job type. Whether you’re doing a capital improvement or a repair, you pay sales tax when you purchase materials from suppliers. If you buy materials out of state or from a vendor that doesn’t charge tax, you owe use tax at the same rate.

The Form ST-8 is your documentation for exempt work. Property owners fill out and sign this form, certifying that the work qualifies as a capital improvement. You keep it on file. If New Jersey audits you and you can’t produce the ST-8 for an exempt job, you may owe the tax plus penalties and interest. Don’t skip this step.

Some jobs mix both types of work. If you’re doing a kitchen renovation that includes capital improvement work like new cabinets and counters alongside repair work like fixing a leaky faucet, you need to separate them on your invoice. The capital improvement labor is exempt with a valid ST-8. The repair labor is taxable.

Setting up your books to track this correctly prevents problems later. Your accounting system should distinguish between taxable repair labor and exempt capital improvement labor for each job. New Jersey bookkeepers who understand contractor accounting can configure your job costing to reflect tax treatment correctly and keep ST-8 certificates organized by project.

Getting this wrong creates liability. If you don’t collect tax on taxable repair work, you still owe it to the state. If you claim capital improvement exemptions without proper ST-8 documentation, those become your responsibility in an audit. New Jersey looks back several years when auditing contractors, so problems compound.

Proper construction job costing builds this tracking into each project from the start. When every job in your books shows whether labor was taxable or exempt and links to the supporting documentation, quarterly filings become accurate and audits become manageable.