CA Form 540 Use Tax: California Use Tax

Use tax is the part of California tax law that almost nobody knows about until they see the line on their return. Here is the short version. California charges sales tax when you buy a taxable item from a seller inside the state. That seller collects the tax at the register and sends it to the state. But what happens when you buy the same item from a seller who is not in California, a website based in another state, a vendor in Oregon, a shop overseas. That out-of-state seller does not always collect California tax. California still wants its cut, because you are going to use, store, or consume that item inside California. So the state shifts the job of paying the tax from the seller to you, the buyer. That tax you owe directly is called use tax, and it is reported right on your California Resident Income Tax Return, which is Form 540.

The point people miss is that use tax is not a second tax on top of sales tax. It is the mirror image of sales tax, set at the exact same rate, and you only owe one or the other on a given purchase, never both. If the seller already collected California sales tax, you owe no use tax on that item. If the seller collected nothing, you owe use tax. The state is not trying to charge you twice. It is closing the gap so that an item bought online from out of state is taxed the same as the identical item bought from a store down the street. Without use tax, every California retailer would be at a permanent price disadvantage against out-of-state competitors, and the state would lose billions in revenue. The California Department of Tax and Fee Administration explains the basic rule in plain terms on its use tax page, which is worth a look if you want the state’s own description.

So why does it land on Form 540, the income tax return, instead of some separate sales tax form. For individuals who are not running a business, California decided the easiest way to collect use tax on personal purchases was to put a line on the income tax return everyone already files. You report the tax you owe on out-of-state purchases right there, and it gets added to your California tax bill or subtracted from your refund. The Franchise Tax Board, which runs the income tax side, hands the money over to the CDTFA, which runs the sales and use tax side. You see one combined number on your 540, but two different state agencies are involved behind the scenes. The instructions for the use tax line live in the official 2025 Form 540 booklet.

The rate question trips people up because California does not have one flat sales and use tax rate. The statewide base is 7.25 percent. On top of that, cities and counties add local district taxes, so the rate you actually pay depends on where you live and use the item. Someone in a low-rate county pays close to the 7.25 percent base. Someone in a city with stacked district taxes can pay 10.25 percent or even 10.75 percent. When you owe use tax on a purchase, you owe it at your own local rate, the rate that would have applied if you had bought the thing at a store in your own town. A 1,000 dollar laptop bought online with no tax collected, used by someone in a 9.5 percent district, generates 95 dollars of use tax.

Now the honest part, because this is where firms either tell you the truth or stay quiet. Use tax on personal purchases is, in practice, largely self-reported, and historically a lot of Californians left the line blank without consequence. That does not make it optional. It is a legal obligation, and the state has gotten far more aggressive about it as online shopping exploded. The reason the line still exists, even after big retailers started collecting tax at checkout, is that plenty of purchases still slip through. Buy from a small Etsy seller, a foreign website, a private party, a niche vendor that has no California presence, and no tax gets collected. You owe use tax on every one of those.

We deal with this constantly for our California clients, because the question of what is taxable and at what rate is not always obvious, especially for people who buy equipment, furniture, art, or electronics from out-of-state sources. If you want the use tax line handled correctly rather than guessed at, that is the kind of detail we cover in our individual tax return preparation work. The federal return has no use tax at all, so the only place this shows up is on the state side. The closest federal cousin is the sales tax deduction on Schedule A, which is a different mechanism we get into elsewhere on this page. For the full picture of how California fits items into the tax base, the rules in Publication 17 describe the federal itemized side that interacts with what you pay the state.

California gives you two ways to figure your use tax on the Form 540 line, and picking the right one depends on how good your records are and how much you actually bought out of state. The first method is to report your actual purchases. The second is to use the use tax lookup table, which estimates your tax based on your income. Most people with normal spending use the table because it is faster and they do not have to dig through a year of receipts. People who made large untaxed purchases, like a 4,000 dollar piece of equipment or a 2,000 dollar furniture order from out of state, are usually required to report those big items separately rather than letting the table cover them.

Start with the actual-purchase method, because it is the cleaner concept. You add up every taxable item you bought during the year where no California tax was collected. Then you multiply that total by your local use tax rate, the rate for the city and county where you live. If your area is at 9.25 percent and you bought 1,000 dollars of untaxed goods, you owe 92.50 dollars in use tax. You report that on the 540 line. This method is exact, and it is the only method allowed for businesses and for certain large purchases. The catch is record-keeping. You have to actually know what you bought untaxed, which means saving order confirmations from out-of-state sellers and checking whether each one charged California tax. A lot of people cannot reconstruct that after the fact, which is exactly why the state built the second method.

The use tax lookup table is California’s shortcut for personal, non-business purchases. Instead of tracking receipts, you look up your adjusted gross income in a table printed in the 2025 Form 540 booklet, and the table gives you an estimated use tax amount. The table assumes that people with higher income buy more untaxed stuff, so the dollar figure climbs as income climbs. The estimate is meant to cover everyday untaxed purchases, the small online orders, the things under a threshold, the items you would never remember individually. The table figure is deliberately modest, often somewhere between roughly 20 and a couple hundred dollars depending on income, because it is only covering routine small purchases, not big-ticket items.

Here is the rule that catches people. The lookup table only covers individual purchases under 1,000 dollars each. If you bought a single item that cost 1,000 dollars or more and no California tax was collected, you cannot bury it in the table figure. You have to add the use tax on that specific item, at your local rate, on top of the table amount. So the correct number for someone who made a large untaxed purchase is the table figure plus the actual use tax on the big item. A person who bought a 3,500 dollar untaxed camera reports the table estimate for their everyday purchases plus 3,500 dollars times their local rate for the camera. Skip that step and the return understates the tax.

Which method should you use. If you kept good records and your untaxed purchases were small, the actual method might give you a lower number than the table, so it can be worth the effort. If you have no records and only made routine purchases, the table is the practical choice and it protects you, because using the official table in good faith is an accepted way to satisfy the obligation. If you made any large untaxed purchase, the method is partly chosen for you, because that item has to be reported on its actual cost regardless. The CDTFA lays out who can use the table and the 1,000 dollar item rule on its use tax page.

One number that matters here is your local rate, because both methods need it for the big items. California rates run from the 7.25 percent statewide base up to about 10.75 percent in the highest-rate cities. If you do not know your rate, the CDTFA publishes a rate lookup by address. Getting the rate wrong by even a point on a large purchase changes the tax by real money, so it is worth confirming rather than guessing at 7.25 percent when your city actually sits at 9.5 percent.

For our California clients, we generally run the table method for routine spending and then ask directly about any large out-of-state purchases during the year, because those are the ones that move the number and the ones the state is most likely to question. That review is built into our individual tax return preparation work, and when a client has a pattern of big untaxed buys we look at it as part of tax strategy consulting so the use tax is not a surprise every April. The use tax line connects to the federal return only through the itemized sales tax deduction on Schedule A, which has its own separate rules described in Publication 17.

The short answer is yes, you can still owe use tax, but a lot less of it than you did before 2018. Something big changed that year. The Supreme Court decided a case called South Dakota versus Wayfair, and it rewrote the rules for when a state can make an out-of-state seller collect sales tax. Before Wayfair, a state could only force a seller to collect tax if that seller had a physical presence in the state, a store, a warehouse, employees. An online retailer with no California building could sell into California all day and collect nothing, which left the buyer owing use tax on every purchase. After Wayfair, states were allowed to require collection based on economic activity alone, meaning a high enough volume of sales into the state, with no physical presence needed.

California responded by passing economic nexus rules. Now any retailer that sells more than 500,000 dollars into California in a year has to register and collect California tax at checkout, even if they have no office or warehouse anywhere near the state. That single change pulled the vast majority of large online sellers into the collection system. Amazon, the big-box retailer websites, the major direct-to-consumer brands, they all collect California tax now. The state also passed marketplace facilitator rules, which make the marketplace itself, not the individual third-party seller, responsible for collecting tax. So when you buy from a small seller through Amazon or eBay, the platform collects the California tax on that seller’s behalf. The result is that for everyday online shopping, the tax usually gets handled at checkout, and you owe no use tax on those purchases because the tax was already collected.

So why does use tax still exist at all. Because the collection net, as wide as it is now, still has holes. Several common situations slip right through it. The first is small out-of-state sellers below the 500,000 dollar threshold. A boutique vendor in another state that sells, say, 200,000 dollars a year nationwide is not required to register in California, so it collects nothing, and you owe use tax on what you buy from it. The second is foreign sellers. Buy directly from a website based overseas, a specialty shop in Europe or Asia that ships to you, and there is often no California tax collected at all. The third is private-party and casual sales. Buy a used item from an individual through a classified listing or a forum, and no business is involved to collect tax, but if the item is taxable and shipped from out of state, use tax can still apply.

There is a fourth category that catches people who think they are safe. Some sellers, even sizeable ones, simply do not collect California tax correctly, whether through error or because they wrongly believe they are not required to. The legal obligation to pay use tax sits with you, the buyer, regardless of whether the seller did its job. If the seller should have collected and did not, you still owe the use tax. You do not get to point at the seller’s mistake. So even in a post-Wayfair world, checking whether tax was actually collected on a given purchase still matters, because the obligation defaults back to you when it was not.

How much does this actually amount to now. For most people, far less than it used to. Ten years ago, a heavy online shopper might have owed real money in uncollected use tax across a year of purchases. Today, with the big platforms collecting at checkout, the routine stuff is mostly covered, and the use tax lookup table figure in the 2025 Form 540 booklet reflects that reality by staying fairly modest. The purchases that still generate use tax tend to be the unusual ones, the foreign order, the niche vendor, the private sale, the large item from a seller that fell below the threshold. The CDTFA still maintains its use tax page precisely because the obligation did not disappear, it just narrowed.

The mistake we see is people assuming that because Amazon collects, use tax is dead and the line can be ignored. It is not dead. It shrank. For our California clients, the practical approach is to use the table for ordinary purchases and then flag the specific transactions that the collection system tends to miss, the foreign buys and the large purchases from small sellers. We handle that in our individual tax return preparation work, and for clients who buy a lot internationally or from specialty vendors, we factor it into tax strategy consulting so the number is right. None of this touches the federal return directly, since there is no federal use tax, though the related sales tax deduction shows up on Schedule A under the rules in Publication 17.

Business use tax runs on the same basic logic as personal use tax, but the reporting, the record-keeping, and the stakes are all different, and a business owner who treats it like the personal line on Form 540 is going to get it wrong. The core rule is identical. If your business buys a taxable item from an out-of-state seller, no California tax is collected, and you use that item in California, you owe use tax at your local rate. Where it diverges is in how the tax gets reported and how closely the state watches. Personal use tax goes on your individual Form 540 line, often using the lookup table. Business use tax usually does not. It typically gets reported through a California Department of Tax and Fee Administration account, on a sales and use tax return the business files directly with the CDTFA, not buried in anybody’s income tax return.

Start with the equipment example, because it is the most common case. A California business buys a 15,000 dollar machine from a manufacturer in another state. The manufacturer does not collect California tax, maybe because it has no California presence or simply did not charge it. The machine gets shipped to the business and used in California. That business owes use tax on the full 15,000 dollars at its local rate. At 9 percent, that is 1,350 dollars. There is no lookup table for this. The business cannot estimate it based on income. It owes the actual tax on the actual purchase, reported on the actual return, because the table is reserved for personal purchases under 1,000 dollars. Equipment, machinery, computers, furniture, tools, all of it follows the actual-cost rule.

The reporting channel is the first real difference. Many California businesses already hold a seller’s permit because they make taxable sales and collect sales tax from their own customers. Those businesses report use tax on their purchases right on the same CDTFA sales and use tax return they already file, on a line for purchases subject to use tax. A business that does not make taxable sales, and therefore has no seller’s permit, may still owe use tax on its purchases, and in that case California can require it to register for a use tax account specifically to report those purchases. The CDTFA describes both situations and who has to register on its use tax page. The upshot is that business use tax lives in the CDTFA system, not on the income tax side, for any business that has or needs an account.

The second difference is scrutiny. The state pays far more attention to business use tax than to the personal line, because the dollars are bigger and the records exist. When the CDTFA audits a business, untaxed out-of-state purchases are one of the first things examiners look at. They pull your purchase invoices, find the ones where no California tax was charged, and assess use tax plus interest and penalties on anything you failed to self-report. A business that bought 80,000 dollars of untaxed equipment over a few years and never reported use tax is looking at a meaningful assessment when the auditor finds it. This is not the casual, lightly-enforced world of the personal use tax line. For businesses, it is a real audit exposure, which is why clean purchase records matter so much.

That brings up the third difference, which is record-keeping discipline. A business needs to track, purchase by purchase, which out-of-state buys had California tax collected and which did not. The ones that did not are the use tax base. Good bookkeeping makes this routine, because every vendor invoice gets coded as you enter it, and the untaxed out-of-state purchases are easy to total at filing time. Sloppy or missing records turn it into a guessing game that falls apart under audit. We build this tracking into our bookkeeping work for California business clients precisely so the use tax number is defensible and not reconstructed from memory years later when an auditor asks.

There is also a planning angle for businesses that personal taxpayers do not have. Some purchases qualify for exemptions or partial exemptions, like certain manufacturing and research equipment, which can reduce the use tax owed on a big machine. Whether a purchase qualifies, and how to document it, is the kind of question worth answering before you buy rather than after, because the savings on a large equipment order can be substantial. That is the sort of analysis we run as part of tax strategy consulting for clients making significant capital purchases.

One last point that confuses owners. The equipment you buy and pay use tax on is the same equipment you depreciate on your federal return. The federal side has no use tax, but the cost of the equipment, including the use tax you paid, becomes part of your depreciable basis on the federal Form 1040 business schedules. So the California use tax you pay on a business machine is not just a state cost, it folds into the federal depreciation figure too. For a sole proprietor, that flows through the business schedule that feeds the 1040, and the income adjustments tie back to Schedule 1. The two systems run separately but the same purchase touches both.

Let us be honest about what happens if you leave the use tax line on Form 540 blank when you actually owed something. For a typical individual with small untaxed purchases, the realistic near-term consequence is often nothing visible, which is exactly why so many people skipped it for years. California does not chase down every taxpayer who underreported 40 dollars of use tax on a few online orders. But near-term invisibility is not the same as no risk, and it is definitely not the same as the line being optional. Use tax is a legal obligation. Reporting it is required when you owe it, and the state has every right to come back and collect it, with interest and penalties, if it later finds untaxed purchases you never reported.

The risk scales sharply with the dollar amount. A person who left the table figure off their return has a small, mostly theoretical exposure. A person who bought a 12,000 dollar untaxed item, a piece of art, a high-end watch, a major furniture order from out of state, and reported no use tax on it, has a real problem if the state ever connects the purchase to them. The CDTFA does receive information about large transactions in various ways, and it actively pursues unreported use tax on big-ticket items. When it does, it assesses the tax you should have paid, plus interest running from the original due date, plus a penalty for failing to report. What would have been roughly 1,140 dollars of use tax on that 12,000 dollar item at 9.5 percent becomes a larger number once interest and penalty are stacked on, and you have lost the chance to simply pay it cleanly on your return.

For businesses, ignoring use tax is a different order of risk entirely, as covered in the business use tax answer above. The CDTFA audits businesses, pulls purchase invoices, and routinely assesses unreported use tax on untaxed out-of-state buys. A business that ignored the obligation across several years can face an assessment in the tens of thousands once an auditor totals the untaxed purchases and adds interest and penalties. The state’s own use tax page exists in part to put taxpayers on notice that this obligation is enforced, not forgotten.

Now the federal connection, because this is where people get confused and assume use tax must show up somewhere on their 1040. It does not. There is no federal use tax. The federal government does not impose a use tax on out-of-state purchases, full stop. The use tax line is purely a California matter, reported only on Form 540 for individuals or through the CDTFA for businesses. Nothing about your use tax flows onto the federal return as use tax, because the federal return has no such line. If you are looking for use tax on your 1040, you will not find it, and that is correct, not an oversight.

The one real federal connection runs through a different door, the itemized deduction for state and local taxes. On the federal Schedule A, a taxpayer who itemizes can deduct either state income tax or state general sales tax, but not both. You pick whichever is larger. For a Californian with a normal salary, state income tax is usually the bigger number, so most people deduct income tax and never touch the sales tax option. But for someone with low state income tax and a year of large taxable purchases, the sales tax deduction can win. And here is the link to use tax. The sales and use tax you paid, including use tax on out-of-state purchases, counts toward that sales tax deduction figure if you go that route. So the use tax you pay California can, indirectly, increase a federal deduction, but only if you choose the sales tax deduction over the income tax deduction. The rules for this choice are spelled out in Publication 17.

The full federal return, of course, runs on Form 1040, with itemized deductions carried over from Schedule A and various income adjustments flowing through Schedule 1. None of those is a use tax line, but the sales tax deduction interaction means the California and federal sides are not entirely separate. For our California clients, we check whether the sales tax deduction beats the income tax deduction in the rare years it might, and we make sure the use tax line on the 540 is reported correctly rather than left blank and hoped over. That review is part of our individual tax return preparation work. For clients with a pattern of large untaxed purchases or business buying, we build the use tax exposure into tax strategy consulting so it is planned for, not discovered. If you want to see how the use tax line ties into the broader California return, the related discussion on California Form 540 itemized deductions covers the deduction side that connects back to all of this. The honest bottom line is that the use tax line is small for most people and large for a few, and the ones it is large for are exactly the ones the state is most likely to pursue.