Importantly, SB 25 is non-suspensory, meaning it does not impose a waiting period or require state approval before closing. As California AG Rob Bonta has emphasized, the law is designed to provide “upfront access to federal merger filings” and “facilitate early information sharing and coordination” between state and federal antitrust officials, rather than to create a duplicative or independent review process.
Who Must File
SB 25 requires a party making a federal HSR filing to provide an electronic copy to the California AG if either of the following conditions is met:
- Trigger 1 – Principal Place of Business. The filing party has its principal place of business in California. Although SB 25 does not define “principal place of business,” the UAPNA commentary defines it as “the place where a corporation’s officers direct, control, and coordinate the corporation’s activities.”
- Trigger 2 – In-State Sales Nexus. The filing party, or a person it directly or indirectly controls, had annual net sales in California of the “goods or services involved in the transaction” of at least 20% of the then-operative HSR size-of-transaction threshold. Under current HSR thresholds, this translates to approximately $26.78 million in annual net California sales, though the figure will shift as the FTC adjusts the HSR threshold annually each February. While SB 25 does not define “goods or services involved in the transaction,” Washington’s guidance suggests that parties should look to the product or service descriptions in the HSR form, meaning the target’s in-state goods and services being acquired are generally captured, while the acquirer retains more flexibility in determining which of its products qualify.
What Must Be Filed and When
The scope of materials required and the filing deadline depend on which trigger applies:
- Under Trigger 1, the filing party must submit a complete electronic copy of the HSR form plus all accompanying documentary materials filed with the federal agencies.
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Under Trigger 2, the filing party initially must submit only the HSR form itself. However, the California AG may subsequently request the additional documentary materials, which the filer must produce within seven days of the request.
In both cases, the filing must be made within one business day of the federal HSR submission. This is a slightly more generous timeline than the “contemporaneously” standard imposed in Colorado and Washington.
Fees, Penalties and Confidentiality
- Filing Fees. The California AG is authorized to charge a fee of $1,000 for filings under Trigger 1 and $500 for filings under Trigger 2, with an additional $500 fee if the AG requests the accompanying documentary materials under Trigger 2. By contrast, Colorado and Washington do not impose filing fees.
- Civil Penalties. Failure to comply with SB 25 can result in civil penalties of up to $25,000 per day of noncompliance, assessed after written notice and a three-business-day cure period. This represents a meaningfully steeper penalty regime than the $10,000 per day maximum in Colorado and Washington.
- Confidentiality. SB 25 includes robust confidentiality protections. The California AG is prohibited from making any component of the HSR form public, and submitted materials are exempt from disclosure under California’s public records law. However, SB 25 does permit the California AG to share filing materials with the FTC, the U.S. Department of Justice, and with other states that have adopted the UAPNA or substantively equivalent legislation, provided those states offer confidentiality protections at least as protective as the uniform act. For any such interstate disclosure, the AG must provide at least five business days’ advance notice to the submitting party.
Comparison with Colorado and Washington
The table below highlights the key differences between California’s SB 25 and the existing mini-HSR regimes in Colorado and Washington:
| Provision | California (SB 25) | Colorado/Washington |
| Filing Deadline | Within one business day of federal HSR filing | “Contemporaneously” with federal HSR filing |
| Filing Fees | Up to $1,000 (Trigger 1) or $500 – $1,000 (Trigger 2) | None |
| Civil Penalties | Up to $25,000/day after notice and three-business-day cure period | Up to $10,000/day with procedural requirements |
| Waiting Period | None (non-suspensory) | None (non-suspensory) |
Practical Implications for Dealmakers
For parties already subject to HSR filing obligations, SB 25 is primarily an administrative compliance exercise rather than a new substantive hurdle. That said, deal teams should keep the following considerations in mind:
- Compliance Workflows. Parties with a California principal place of business or that meet the California sales-based nexus should implement parallel processes to transmit a complete electronic copy of the HSR form (and, where applicable, documentary materials) to the California AG within one business day of the federal filing.
- Deal Timing and Documentation. Although SB 25 does not impose a waiting period, the growing patchwork of state mini-HSR regimes may affect overall deal timing, closing conditions and risk allocation in merger agreements. Parties should consider whether state filing obligations should be referenced in regulatory covenant provisions.
- Earlier State Engagement. SB 25 provides the California AG with earlier access to transaction information, which may result in more routine and earlier outreach from the California Department of Justice in transactions with a California nexus. This early access may also lead to increased coordination with federal enforcers and other state AGs.
- Broader Antitrust Reform on the Horizon. SB 25 focuses narrowly on pre-merger notification procedures, but California’s Law Revision Commission is actively considering amending the Cartwright Act to address anticompetitive mergers substantively. This follows recent Cartwright Act amendments, effective Jan. 1, 2026, that extended coverage to certain algorithmic pricing systems and lowered pleading standards in antitrust litigation.
Looking Ahead: A Growing State-Level Trend
By design, SB 25 is firmly anchored to the federal HSR framework rather than charting an independent California notification path with its own novel thresholds, forms or substantive presumptions. The law asks only for a copy of what the federal HSR process already demands, on a closely synchronized timetable, and draws on existing federal confidentiality standards, definitions and threshold calibration.
California’s enactment of SB 25 is part of a broader, accelerating movement toward state-level pre-merger oversight. Legislatures in Indiana, New York, the District of Columbia, Hawaii and West Virginia are all considering similar legislation. Notably, New York’s proposed bill would go further than the UAPNA model, requiring “any person conducting business” within the state — regardless of in-state revenues — to submit HSR filings and accompanying materials to the New York AG.
The proliferation of these regimes, combined with states’ increasing willingness to independently challenge mergers in court — as demonstrated by Colorado’s and Washington’s independent lawsuits to block a proposed merger of two large grocery store companies and multiple states’ interventions in recent tech and telecom deals — signals that state antitrust enforcement is becoming a permanent and significant feature of the M&A landscape. Deal parties and their advisors should prepare accordingly.
