Many people, when they prepare their California income tax return, are interested in deductions, credits, and refunds, and never pay attention to one of the small lines on Form 540, the Use Tax line. While it may appear negligible, if the California Department of Tax and Fee Administration (CDTFA) concludes that tax was due on some of the purchases, there may be additional tax assessments, interest, and penalties for failing to report use tax.

With the rise of online shopping, it is more crucial than ever to understand California’s use tax regulations for consumers and businesses. Always choose a qualified tax professional (like an IRS tax attorney) who can help you during difficult times.
What is California Use Tax?
Use tax is a tax on the use of taxable goods that have been purchased without paying California sales tax. This is generally applicable to purchases from out-of-state retailers for use, storage, or consumption in California.
Typically, the rate for use tax will be the same as the sales tax rate in your area. It’s for the sake of promoting consistency in taxation of purchases from out-of-state sellers with those made from in-state sellers.
Does Use Tax Apply to Your Transaction?
Use tax may be due when:
- Bought goods from a seller in another state who was not a California seller.
- While traveling outside of California, you purchased furniture, electronics, tools, or equipment and took them home.
- You placed an order for items from another state for your personal or business needs.
- Purchased items from marketplaces or sellers that, at the time of purchase, did not collect California sales tax.
A common misinterpretation by many taxpayers is that if they did not pay sales tax at checkout, they don’t need to pay sales tax. In many instances, the law in California still requires the purchaser to report and pay the use tax.

How Does the CDTFA Track Use Tax?
The California Department of Tax and Fee Administration has vastly enhanced its capacity for determining what purchases are taxable.
The agency can request information from:
- Retailer sales records
- Marketplace facilitator reporting
- Business purchase records
- Audit examinations
- The documentation associated with shipping and transactions. Documents regarding shipping and transactions
- Information provided by other tax authorities.
Moreover, many marketplace facilitators are now required to automatically collect California sales tax as a result of marketplace facilitator laws. Even if you buy it, however, some may still have to be self-reported as use tax. Hire an experienced tax expert who can guide you through the payroll tax audit process.
Why does the Form 540 Use Tax Line Matter?
The Use Tax section of the Form 540 provides a convenient means of reporting eligible purchases by California taxpayers when filing their income tax.
Failure to read this section may result in:
- Additional tax assessments
- Interest charges
- Points will be deducted in some cases
- More questions will be asked during further tax inspections.
It is easier and cheaper to report use tax voluntarily than to have it examined.
Tips on Staying Compliant
With good bookkeeping, tax reporting is easier.
Here are some of the best practices to consider:
- Keep receipts for all significant purchases made online and out-of-town.
- Don’t presume that no sales tax has been collected if California sales tax was not collected.
- Maintain business vs. personal records.
- Check yearly credit card bills for undetected spending.
- Accurately report a qualifying purchase on your California return.
If you are making regular high-dollar purchases from vendors outside your state, it can save you a lot of time during tax season to keep well-organized records.
Form 540’s California Use Tax line is often forgotten about, but it has an important part to play in state tax compliance. The growth and increasing sophistication of e-commerce and the use of more sophisticated data matching and retailer reporting by tax authorities make it easier to identify untaxed purchases.
Knowing when use tax is applicable, maintaining detailed purchase records, and reporting any use tax to the CDTFA can minimize any unnecessary interest, penalties, and future correspondence from the CDTFA.
When you are not sure whether an item is subject to use tax or if you have several out-of-state transactions, it is best to consult a qualified California tax professional to determine if the purchase is subject to use tax or to help ensure that the return is complete and accurate.