California SaaS Sales Tax Starts January 1, 2027: What to Do Now

This post covers California sales and use tax and is general information, not tax advice for your specific situation.

For more than three decades, California did not tax software delivered electronically. That ends on January 1, 2027, when SB 122 (signed June 29, 2026) pulls prewritten software and SaaS into the definition of tangible personal property. If you sell software to California customers, you have roughly four months to figure out whether you are now a sales tax collector, and if you buy software, your stack is about to cost 7 to 10 percent more.

Most founders will hear about this in December, from a Slack message forwarded by their CFO or a panicked email from their billing vendor. That is the expensive way to find out. The registration window with the California Department of Tax and Fee Administration (CDTFA) opens 90 days before the effective date, which means October 1, 2026, and registration volume is going to spike.

What SB 122 Actually Taxes

The law expands “tangible personal property” to include digital products, defined as prewritten computer software transferred on physical media, transferred electronically, or accessed remotely. The delivery method no longer matters. A perpetual license on a USB drive, a downloaded desktop app, and a browser-based subscription are all treated the same way.

That last category is the one that changes everything. “Accessed remotely” is what brings SaaS into the base for the first time. If your customer pays for the right to access, use, download, or manipulate your software, that is a taxable sale in California. Enterprise platforms, seat-based subscriptions, and self-serve monthly plans are all in scope.

What Stays Exempt

Three carve-outs matter for most startups.

Custom software remains exempt. The statute protects software prepared to the special order of a single customer, even when it incorporates preexisting components. The catch is durability: that exemption disappears the moment the software is held or exists for general or repeated sale, even if it started as a one-off build. Agencies and dev shops that productize a client engagement should not assume the original exemption travels with it.

Infrastructure as a Service and Platform as a Service are excluded, as are digital assets, streaming music and video, e-books, and video games. The line between PaaS and taxable SaaS is going to generate arguments, and CDTFA has already said it expects to resolve some of this through litigation.

Services that are primarily human effort stay exempt, even when delivered through a software interface. CDTFA is applying a “true object” test to bundled offerings: if the customer is buying access to software functionality, it is taxable, and if the customer is buying human work that happens to arrive through a portal, it is not. Anyone selling a managed service with a dashboard, or a consulting engagement with a login, needs to price and invoice those components separately before January.

Whether You Have to Collect at All

Taxability and collection obligation are two different questions. You only have to register and collect if you have nexus in California, and for remote sellers that means exceeding $500,000 in gross sales to California customers in the current or prior calendar year.

Here is the part founders miss: newly taxable software revenue counts toward that threshold. A company that was comfortably under $500,000 in taxable sales because none of its revenue was taxable may now cross it on total California ARR alone. Run the number on gross California sales, not on what you previously treated as taxable.

If you are a seed-stage company with $200,000 in California revenue, you have no collection obligation yet, but you do have a modeling problem (see the burn section below) and you should know where the threshold sits, because crossing it mid-year triggers registration.

The $5 Million Enterprise Carve-Out

SB 122 includes an unusual provision. When a single seller’s annual digital product sales to one purchaser exceed $5 million, the collection obligation flips: the seller stops collecting and the purchaser self-assesses and remits use tax directly to CDTFA.

For most startups this is irrelevant. For anyone selling large enterprise contracts, it is a billing system requirement, because the threshold applies per customer relationship and it applies in the aggregate across the year. That means the same customer can be taxable in Q1 and self-assessing in Q3. Your billing logic needs to track cumulative annual sales per account, not just per invoice.

Which Rate You Charge and How You Source It

California’s rate is 7.25 percent statewide plus local district taxes, so combined rates run from 7.25 percent to over 10 percent depending on the customer’s location. San Francisco is currently 8.625 percent.

Sourcing follows a hierarchy based on the purchaser’s known California address: billing address first, then shipping or delivery address, then the address on the payment instrument, then any other known mailing address. There is also a presumption of California use for digital products bought elsewhere and used in the state within 90 days of sale.

Two practical consequences. First, whatever address field your billing system treats as authoritative is now a tax determination, which means a customer who typed their old apartment into Stripe three years ago is a compliance problem. Second, multiple points of use is genuinely unresolved. The statute says use occurs where the person accessing the software is located, but it provides no allocation method for a customer with employees in twelve states. CDTFA has floated purchaser-side exemption certificates and apportionment models borrowed from other states, and none of it is final.

What Happens to Contracts That Straddle January 1

CDTFA’s position from the July workshop is that taxability requires both a right to use and consideration provided on or after January 1, 2027. Renewals dated on or after the effective date are generally taxable. What the department pointedly declined to commit to is whether the contract date or the payment date controls for multi-year prepaid agreements.

That ambiguity sits directly on top of the deals you are signing right now. Every California contract signed between today and year end should include a tax pass-through clause that lets you add sales tax when it becomes applicable, whether or not the current MSA contemplates it. Retrofitting that clause in January means renegotiating with customers who have already budgeted, and eating the tax when they say no.

The Burn Problem Nobody Is Modeling

Everything above is the seller’s view. Now flip it.

A typical Series A software company runs 40 to 60 SaaS vendors. Most of that spend is with California-facing vendors or vendors who will register in California, and starting January 1, most of it carries 8 to 9 percent tax that was not in your 2027 budget. On $600,000 of annual software spend, that is roughly $50,000 of new cash cost, on a line item founders usually model as flat.

If a vendor does not collect, the obligation does not disappear. California use tax is self-assessed by the purchaser. Companies that have never filed a use tax return are going to accrue exposure quietly across 2027 and discover it in a diligence process.

Two things to do on the buy side: rebuild the 2027 software line with tax included rather than treating it as noise, and add a use tax accrual to your month-end close so unbilled tax shows up as it happens instead of as a surprise.

What to Do Before January 1

1. Classify every revenue stream as prewritten software, custom software, or human-effort service, and unbundle anything that mixes them in a single line item.
2. Total gross California sales against the $500,000 threshold, counting revenue that was not previously taxable, and register with CDTFA in October if you clear it.
3. Add a tax pass-through clause to every California contract and renewal signed from now on.
4. Collect valid California resale and exemption certificates from B2B customers who qualify, because you cannot skip charging tax without the certificate on file.
5. Clean up billing addresses and configure rate calculation by customer location, then model the buy-side cost increase on your own software stack.

CDTFA published a discussion paper with draft emergency regulations on September 1, 2026, and expects to submit final rules in early December. Some answers, particularly on multiple points of use and bundling, are still moving. That is an argument for getting the classification and registration work done now, not for waiting to see what the final regulations say.

SB 122 lands on top of the California obligations startups already carry. The payroll side is in why your 2026 California payroll taxes jumped, the filing calendar in every tax deadline your Delaware / California startup needs to know, and the wider picture in running a startup in San Francisco: the compliance reality. If charging tax means reworking how you invoice, the billing mechanics are in usage-based billing and revenue recognition for AI companies, and the buy-side burn math is in your AI startup burns differently than SaaS.

If you want to talk through how this applies to your company, book a call.

Anelya Grant is the founder of AG Accounting Inc., an accounting firm serving tech startups and healthcare organizations. She is also co-founder of Loopfour.ai.