California Sales Tax Nexus: What Out-of-State Sellers Need to Know in 2026

The $500,000 Threshold: Exactly How It Works

California's economic nexus threshold is $500,000 in gross sales of tangible personal property, measured against the preceding or current calendar year. One dollar over that number creates a registration obligation with the CDTFA. There is no transaction count. There is no end-of-year grace period. There is no dip-back-under reset.

The transaction count rule is worth addressing directly because a lot of sellers are still tracking it. California eliminated its 200-transaction threshold on April 25, 2019. If you have been keeping your order count under 200 as a compliance strategy, that approach stopped working more than six years ago.

The day your California sales cross $500,000, you have nexus. The clock on your registration obligation starts that day, not at quarter end, not at year end, not when you file your annual tax return. Every taxable sale you make to a California customer after that point without being registered is additional unregistered liability.

California Nexus Trigger Quick Reference: Threshold is $500,000 in gross sales of tangible personal property. Lookback period is the preceding or current calendar year. All sales channels combined count toward the total, including marketplace sales. Nexus triggers the day you exceed the threshold. The transaction count threshold was eliminated April 25, 2019 and does not exist. Source: California Department of Tax and Fee Administration (CDTFA).

Pull your California sales across all channels for the last 12 months. If you are above $500,000, you have nexus. If you crossed that line at any point in the last three years and never registered, you have unregistered retroactive exposure. That exposure grows every month you wait.

SB 122: What's Coming January 1, 2027 (And Why Digital Sellers Should Act Now)

California passed SB 122 as part of its 2026-27 budget package, extending sales and use tax to prewritten software, SaaS, and remotely accessed software. The effective date is January 1, 2027. That date is close enough that software and digital product businesses need to be planning now, not in December.

Here is what SB 122 actually covers. The law amends California's definition of tangible personal property to include prewritten computer software regardless of how it is delivered, including downloaded software, subscription-based SaaS, and cloud-accessed applications. A sale under SB 122 includes any transfer of the right to open, view, access, download, copy, update, store, or manipulate a digital product. That language captures most modern software delivery models.

What it does not cover is equally important. SB 122 does not apply to custom software, digital audio and video works, digital books, video games, infrastructure-as-a-service, or cryptocurrency. If your product is custom-built for a specific customer, it remains exempt. If you run a SaaS platform or sell prewritten software subscriptions, you are in scope starting January 2027.

The nexus implication for businesses that are not yet registered in California is direct. Once SB 122 takes effect, California sales of covered software and SaaS will count as sales of tangible personal property for purposes of the $500,000 economic nexus threshold. A software company currently running $450,000 in California SaaS revenue that has never registered because it believed those sales were nontaxable will cross the threshold on day one of 2027, with no grace period. If that company also has any physical product sales in California, it may already have nexus today.

SB 122 business impact summary: SaaS providers (prewritten, subscription-based) have sales that become taxable TPP effective Jan. 1, 2027. Cloud-accessed software platforms are covered under remote access, same rules as downloaded software. Software licensors (perpetual or term) are taxable regardless of delivery method. Custom software developers remain exempt; modifications taxable only to extent of modification. Mixed physical and software businesses may have combined sales that push total over $500,000 threshold. IaaS providers are explicitly excluded. (Cal. S.B. 122, 2025-2026 Reg. Sess., ch. 23, effective Jan. 1, 2027.)

The Marketplace Trap: "The Platform Handles My Sales Tax"

This is the single most common misconception we see from multi-channel sellers. The logic goes: Amazon is a marketplace facilitator, Amazon collects and remits California sales tax on my Amazon orders, therefore my California sales tax obligation is covered. The first two parts of that logic are correct. The conclusion is not.

Marketplace facilitator status means the platform collects and remits tax on sales it facilitates. It does not cover your independent obligation on sales you make through other channels. A seller running $400,000 through Amazon and $200,000 through their own Shopify storefront has $600,000 in total California sales. Amazon handled tax collection on the $400,000. No one handled tax collection on the $200,000 in direct sales. That $200,000 in unremitted tax is the seller's liability.

Channel breakdown: Sales through Amazon (marketplace facilitator) are collected and remitted by Amazon. Sales through your own website or storefront are your responsibility. Sales through Shopify (where Shopify acts as facilitator) are collected by Shopify. Sales through channels where you are the merchant of record and through smaller platforms that are not marketplace facilitators are your responsibility.

There is a second layer that compounds the problem. Your marketplace sales count toward your $500,000 threshold even when the platform is handling tax collection on those orders. The threshold test is about your California revenue, not about which channel collected the tax. A seller with $300,000 in Amazon sales and $210,000 in direct website sales has crossed the threshold. Both channels feed the same total for nexus purposes.

If you sell on multiple platforms into California, map each channel's California sales separately and add them together. That is the number that controls your nexus status.

If You Already Have Unregistered Nexus: VDA vs. Waiting

Coming forward proactively through California's Voluntary Disclosure Program is almost always better than CDTFA finding you first. That is not a close call.

The VDA program, administered through the CDTFA, allows sellers who come forward before CDTFA initiates contact to limit their lookback period to three years plus the current period. Penalty waivers are available. You control the scope and the timing. A seller with three years of unregistered California exposure, coming in through VDA, is looking at a defined and manageable window.

A seller who waits and gets audited faces a different calculation. Under Cal. Rev. and Tax. Code section 6487, the general statute of limitations is three years, but it extends to eight years for substantial underpayment, and there is no statute of limitations at all where there is fraud or a failure to file a return. Waiting does not make older periods disappear. It makes them available to CDTFA without the protections that VDA provides.

VDA vs. CDTFA Audit comparison: In a voluntary disclosure, the lookback period is 3 years plus current period, penalties may be waived, you control scope and timing, and you initiate contact with high strategic leverage. In a CDTFA audit, the lookback extends up to 8 years for substantial underpayment and is unlimited for fraud or failure to file under Cal. Rev. and Tax. Code sec. 6487, penalties are assessed at auditor's discretion, CDTFA controls scope and timing, CDTFA initiates contact, and your strategic leverage is low.

The math on this is straightforward. A seller with two years of unregistered exposure has roughly the same lookback window under VDA and under a standard audit. A seller with five or six years of exposure is looking at a substantially larger audit window if they wait. Every month of inaction after crossing the $500,000 threshold is another month of potential exposure that VDA cannot cap if CDTFA gets there first.

The VDA window is open. CDTFA is not waiting.

What Nexus Actually Requires You to Do

Once you have California nexus, three obligations attach. You must register for a CDTFA seller's permit. You must collect California sales tax from California customers on taxable sales. You must file returns on the schedule CDTFA assigns, which runs monthly, quarterly, or annually depending on your volume.

All three obligations begin retroactively from the date you first exceeded the $500,000 threshold, not from the date you discover you had nexus. A seller who crossed in February and registers in November owes for every taxable sale to California customers across those nine months. The discovery date is irrelevant to the liability calculation.

Register for your CDTFA seller's permit directly at cdtfa.ca.gov. You will need your basic business information, your federal EIN, and a description of your products. Be aware that registration opens the question of prior-period liability, which means the registration process and the VDA process are often best handled together, with a clear plan for how you are addressing the retroactive period before you file anything.

For sellers who have already received a CDTFA notice or audit letter, our California Sales Tax Audit guide covers what to do next.

Know Your Exposure Before CDTFA Does

The CDTFA has purchase data from Amazon, Shopify, and payment processors. That data is matched against registration records on an ongoing basis. The question is not whether CDTFA can identify unregistered sellers. The question is whether you are registered before they run the match on your account.

Sellers who come forward through VDA control the terms. Sellers who get flagged first do not. The difference frequently runs into tens of thousands of dollars in penalties alone, on top of the tax owed, and it removes the single most valuable tool available to unregistered sellers: the ability to define the scope of the review.

Create your free Sales Tax Helper account and find out where you stand before CDTFA does.

Frequently Asked Questions

What is California's economic nexus threshold for sales tax?

California's economic nexus threshold is $500,000 in gross sales of tangible personal property, measured against the preceding or current calendar year. Per the CDTFA, nexus triggers the day you exceed that amount, not at quarter end or year end.

Does California have a transaction count threshold for sales tax nexus?

No. California eliminated its 200-transaction count threshold on April 25, 2019. The only threshold that applies today is the $500,000 gross sales figure. If you have been tracking transaction count as a compliance tool for California, stop.

What does California's SB 122 mean for digital sellers?

SB 122, passed as part of California's 2026-27 budget, extends sales and use tax to prewritten software, SaaS, and remotely accessed software effective January 1, 2027. Once in effect, sales of covered digital products will count toward the $500,000 economic nexus threshold as tangible personal property. Software companies that have not registered in California because they believed their digital sales were nontaxable services need to revisit that position before January 2027. Custom software, digital audiovisual works, digital books, video games, and infrastructure-as-a-service are excluded. (Cal. S.B. 122, 2025-2026 Reg. Sess., ch. 23, effective Jan. 1, 2027.)

Do I need to collect California sales tax if I only sell online?

Yes, if your California sales exceed $500,000 in the preceding or current calendar year. Physical presence in California is not required. Remote sellers with no employees, warehouses, or offices in the state are subject to this threshold. Selling exclusively through e-commerce does not change the analysis.

Does Amazon or Shopify collecting sales tax mean I have no California nexus obligation?

No. Marketplace facilitator status means the platform collects and remits tax on the sales it facilitates. It does not eliminate your registration obligation or your liability for sales you make through your own channels. Your marketplace sales also count toward your $500,000 threshold even though the platform handled tax collection on those orders.

What happens if I have had California nexus but never registered?

Your liability for uncollected and unremitted California sales tax begins from the date you first exceeded the threshold, not from the date you learn about the issue. Penalties and interest accrue across the unregistered period. California's Voluntary Disclosure Program can limit your lookback to three years plus the current period and may allow penalty waivers, but only if you apply before CDTFA contacts you first.

How far back can the CDTFA audit an unregistered out-of-state seller?

Under Cal. Rev. and Tax. Code section 6487, the general statute of limitations is three years. It extends to eight years for substantial underpayment. There is no statute of limitations where there is fraud or a failure to file a return. Waiting to register does not close older periods. It leaves them open for CDTFA to access if they initiate an audit before you come forward.

What is California's Voluntary Disclosure Program for remote sellers?

California's VDA program is administered by the CDTFA and allows eligible sellers to come forward proactively, limit their lookback period to three years plus the current period, and apply for penalty waivers. Details and the application process are available at cdtfa.ca.gov. Sales Tax Helper can help you evaluate your eligibility, prepare your application, and structure the disclosure to protect your interests.

Does California have a separate rule for SaaS or software after SB 122?

Beginning January 1, 2027, prewritten software and SaaS are taxable in California under SB 122 regardless of delivery method. Remote and cloud-accessed software is covered under the same rules as downloaded software. Custom software remains exempt. Businesses with California SaaS revenue approaching $500,000 should assess their nexus position and VDA eligibility before the January 2027 effective date. (Cal. S.B. 122, 2025-2026 Reg. Sess., ch. 23, effective Jan. 1, 2027.)

How do I register for a California seller's permit?

Register directly through the CDTFA at cdtfa.ca.gov. You will need your business information, your federal EIN, and a description of your products. Before you register, understand that doing so triggers questions about prior-period liability. If you have had California nexus for more than a few months before registering, handling the registration alongside a VDA application or a retroactive liability review typically produces a better outcome than registering cold.