How does a voluntary filing differ from a mandatory declaration?

Mandatory declarations are required by regulation for certain foreign-government-linked deals or investments in U.S. critical technology, infrastructure, or sensitive data businesses. Voluntary filings cover everything else and are at the parties' discretion.

Can CFIUS still review a deal that was not voluntarily filed?

Yes. CFIUS's non-notified transactions team can call in deals years after closing, which is a major reason parties file even when not legally required to.

Voluntary CFIUS Filing | Model Diplomat

Q: What is the 'safe harbor' benefit?

Once CFIUS concludes review of a notified transaction without action, the President generally cannot later order divestiture based on the facts disclosed, giving parties closing certainty.

A voluntary CFIUS filing is a submission that parties to a cross-border transaction make to the Committee on Foreign Investment in the United States (CFIUS) even when no statute compels them to notify. CFIUS, chaired by the Treasury Secretary, reviews foreign investments in U.S. businesses for national security risks under Section 721 of the Defense Production Act of 1950, as amended by the Foreign Investment Risk Review Modernization Act of 2018 (FIRRMA).

Most deals fall outside the narrow set of mandatory declarations (which generally cover certain foreign-government-controlled investments and deals involving U.S. businesses in critical technologies, critical infrastructure, or sensitive personal data — the "TID U.S. businesses"). For everything else, notifying CFIUS is at the parties' discretion. They file voluntarily to obtain a safe harbor: once CFIUS concludes review and does not act, the President generally cannot later order divestment based on facts known at the time.

Parties can choose between two instruments. A short-form declaration (roughly five pages) triggers a 30-day assessment after which CFIUS may clear the deal, request a full notice, or take no action. A full written notice initiates a 45-day review, extendable by a 45-day investigation and, in rare cases, a 15-day presidential decision period. Filing fees, introduced in 2020, scale with transaction value up to USD 300,000.

Reasons to file voluntarily include investor risk management, lender or insurer requirements, and avoidance of a later non-notified review by CFIUS's monitoring staff, which has expanded significantly since FIRRMA. The cost is disclosure of sensitive deal information, longer closing timelines, and the possibility that CFIUS imposes mitigation agreements — for example, governance restrictions, security officers, or supply assurances — as a condition of clearance.

Notable cases shaping practice include the blocked Broadcom–Qualcomm bid (2018), the forced unwinding of Beijing Kunlun's ownership of Grindr (2019–2020), and ByteDance's ongoing disputes over TikTok. Together they illustrate why many non-mandatory deals nonetheless file.

Voluntary CFIUS Filing

Frequently asked questions