The Opportunity Zone working capital safe harbor

It is a rule in the Treasury regulations that lets a Qualified Opportunity Zone Business (QOZB) treat cash, cash equivalents and debt instruments with a term of 18 months or less as reasonable working capital for up to 31 months while it builds or buys the property its business needs.^2,3 Without it, a startup QOZB holding investor cash would fail the 5% limit on nonqualified financial property, which §1400Z-2(d)(3) imports from §1397C(b)(8), and the 70% tangible property test on day one.¹

The safe harbor belongs to the QOZB. A Qualified Opportunity Fund (QOF) cannot use it; the regulations make it available only to QOZBs.⁴ That is why almost every development fund invests through a QOZB. See the QOF 90% asset test.

During a valid plan period, the safe harbor protects every QOZB test that idle cash and unfinished property would otherwise fail.^4,5

The plan can cover development of the trade or business itself, not just a building: the regulations allow the written designation to include developing a trade or business in the zone as well as acquiring, constructing or substantially improving tangible property.^4,3

A QOZB can string together overlapping or sequential safe harbor plans for a total of up to 62 months, if it receives multiple non-de minimis cash infusions and each later infusion is part of a consistent plan covered by the first safe harbor.^4,6 The 62 months run from the first covered infusion, and later infusions do not extend that outer limit.¹⁴

The extension is designed for multi-phase projects and startups that raise money in stages. It does not let a single infusion sit for 62 months: each plan still needs its own written designation and schedule, and each must be spent substantially as planned.^4,5

Delay caused by a government's action on a completed application tolls the safe harbor period, but only where no other action could reasonably be taken to improve the property during the delay. Tolling is not automatic and applies only if the application was completed during the 31-month period.^4,5

If the QOZB is located in a federally declared disaster area, it can receive up to 24 additional months to spend the working capital.^5,12 Market downturns, financing delays and contractor problems are not grounds for tolling.

If cash is not used substantially as the written plan and schedule describe, the safe harbor is lost for that cash, and the QOZB must meet the 5% NQFP limit and the 70% test without it. That can disqualify the QOZB, which in turn removes the QOF's interest from QOZ property for the fund's 90% test.^2,13

Current rules do not provide a general procedure for modifying a plan. Notice 2026-55 asks whether QOZBs should be permitted to modify an existing working capital safe harbor plan, with comments due November 23, 2026.^7,8 Until rules change, draft plans with realistic schedules and enough description to cover foreseeable changes in design or sequencing.

Often not, if the clock starts before power is secured. In Dominion Energy's Virginia territory, connections for data centers above 100 MW were reported to face additional delays of one to three years, for total waits of up to seven years.⁹ Equipment adds its own lead times, which Cushman & Wakefield's 2026 cost guide cites as a driver of rising costs and contingencies, with all-in greenfield costs of $8.9 million to $23.3 million per MW.¹⁰

Practical responses include acquiring land and securing an interconnection agreement with non-QOF capital before the first QOF infusion, phasing a campus so each phase's plan covers a realistic build, ordering long-lead equipment early in each plan, and choosing sites where capacity is already available. Demand is not the constraint: federal researchers estimated U.S. data centers used about 4.4% of U.S. electricity in 2023 and could use 6.7% to 12% by 2028.¹¹ The schedule is. See data center power timelines and the Opportunity Zone clock, power interconnection for Opportunity Zone data centers and the data center development timeline.

A plan should read like a construction budget tied to a calendar. Sponsors typically include the items below; the regulations require the written designation and schedule, and the rest is evidence that use was consistent.^2,4

Plans are reviewed under the QOZB's tests and the QOF's Form 8996 reporting. See managing a data center QOZB.