Vertiv’s order backlog was $15.0 billion on December 31, 2025, up 109% in a year, on a fourth-quarter book-to-bill of ~2.9x. That was the last time the company printed the number. The April 22 and July 29, 2026 releases carry no backlog, no orders and no book-to-bill. What the filings still carry is the deposit line: current deferred revenue went from $1.81 billion to $3.63 billion in six months. Our estimate for the backlog Vertiv is no longer publishing is $16 to $20 billion at June 30, 2026, central case ~$17.4 billion, and the Open Factory Lead-Time Monitor will carry the range until the FY2026 10-K prints the real figure in February 2027.
This piece covers what Vertiv said when it pulled the metric, what deferred revenue does and does not measure, the seven quarters where both numbers exist, what Eaton, ABB, GE Vernova, Schneider, nVent and Modine disclosed for the same period, the three cases and the ceiling, and, behind the wall, the quarter-by-quarter table through December 2026 and what it does to 2027 delivery slots.
Source: Open Factory Lead-Time Monitor (compiled from Vertiv 8-K earnings exhibits, 10-K and 10-Q via SEC EDGAR XBRL; as of July 2026)
Data: backlog-vs-deferred-revenue.csv
Backlog ran $7.2, $7.9, $8.5, $9.5 and $15.0 billion over the five quarters to December 2025, then stops; deferred revenue ran $1.06 to $1.81 billion over the same five quarters, then added $0.65 billion and $1.17 billion in the two quarters with no backlog to compare it to.
The Disclosure That Ended in February
For nine straight quarters Vertiv’s release carried a book-to-bill and, in most of them, a dollar backlog: 1.3x and $5.5 billion in Q4 2023, 1.5x and $6.3 billion in Q1 2024, ~1.2x and $8.5 billion in Q2 2025, ~1.4x and $9.5 billion in Q3 2025. The Q4 2025 release of February 11, 2026 printed organic orders up ~252% year over year, ~117% sequentially, and the $15.0 billion. Then, on the same call, CEO Giordano Albertazzi said Vertiv would stop reporting quarterly orders, order forecasts or backlog with earnings, on the grounds that lumpiness in large orders creates “excessive volatility,” while continuing to disclose the year-end backlog in the 10-K. Two months later the CEO described first-quarter EMEA bookings as strong even as the company does not disclose orders, which is why the OEM Disclosure Scorecard now scores Vertiv’s backlog cell as annual rather than quarterly.
The 10-K still defines the thing we are estimating. Backlog is “product and services for which a customer purchase order or purchase commitment has been received and which has not yet been delivered,” and “the majority of the combined backlog as of December 31, 2025 is considered firm and is expected to be shipped within the next 12 to 18 months.” The same document attributes the doubling to “customer orders being placed in advance of our ability to fulfill them.” On the February call the CEO added that backlog consists of binding purchase orders, and the CFO said the large fourth-quarter orders “came with larger advanced payments.” That sentence is the method: the deposits stay on the balance sheet every quarter, and they are the only series that moves with the orders.
Vertiv is not alone. nVent printed a record $2.6 billion backlog on May 1, 2026 and its July 31 release carries no backlog figure at all; Schneider Electric’s H1 2026 release says “record backlog” and gives no number. The Book-to-Bill League Table counts eight electrical and cooling OEMs that print a ratio or a backlog for the quarter to June 2026 and ten that do not; the league table article ranks them, and Vertiv is the one that moved from the first group to the second mid-cycle.
What Deferred Revenue Measures
Vertiv’s revenue policy says that “payments received in advance for service arrangements or product delivery are recorded as deferred revenue and recognized in net sales when the revenue recognition criteria are met.” Current deferred revenue is therefore the stock of customer cash sitting against undelivered product plus prepaid service, and the noncurrent piece, $122.6 million at June 30, 2026, is described in the 10-Q as “primarily maintenance, extended warranty and other service contracts,” so the current line is the one that tracks equipment. The 10-Q also gives the drawdown: $604.8 million of the opening balance was recognized as revenue in the second quarter and $1,277.3 million in the first half. Add the drawdown back to the change in the balance and the gross inflow of new customer cash was $1.32 billion in Q1 2026 and $1.78 billion in Q2, $3.10 billion in six months, against $805 million in the first nine months of 2025.
The useful ratio is deferred revenue divided by backlog, which we can compute for the seven quarters where Vertiv published both. It sat between 11.6% and 14.8% from December 2023 to December 2025, mean 13.0%, and it was 12.1% on the day the backlog disclosure stopped. Our slot-economy piece plotted the same deferred revenue against quarterly sales (0.30x to 0.54x for eleven quarters, then 0.63x, 0.93x, 1.11x); this piece uses backlog as the denominator because backlog is what a buyer is queued behind.
Source: Open Factory Lead-Time Monitor
The seven disclosed quarters read 11.6%, 11.7%, 14.8%, 13.9%, 14.8%, 11.9% and 12.1%; the low, mid and high cases for June 2026 require 23.3%, 20.9% and 18.4%, so every case assumes customers are now paying at least 4 points more cash per dollar of order than they did in 2024 and 2025.
That assumption is why the estimate is a range and not a point. Had the deposit ratio stayed at 11.6% to 14.8%, $3.63 billion of deferred revenue would mean a backlog of $24.6 to $31.3 billion at June 30, 2026, a book-to-bill above 2.5x in both undisclosed quarters. No peer printed that, and the CEO’s own reason for pulling the metric was that Q4’s lumpiness was not representative. The Datacenter MEP Cost Table carries GE Vernova’s turbine reservations at ~21% of contract value and Modine’s chiller capacity deposit at 4.1%, so a Vertiv ratio drifting from 12% toward 20% as project sizes grow is the ordinary direction of travel. $25 to $31 billion is the ceiling the balance sheet permits, not the estimate.
Peer Read-Across for the Two Blind Quarters
The second constraint is what everyone else booked. In the quarter to June 30, 2026, Eaton’s Electrical businesses ran a 1.2 rolling-twelve-month book-to-bill with total Electrical backlog up 43%; ABB Electrification booked $7.23 billion against $5.20 billion of revenue, 1.39x, with backlog up 57% to $13.7 billion; GE Vernova Electrification booked ~1.7x with equipment backlog up 69% to $40.6 billion; Trane ran 1.23x with backlog up 70% to $12.1 billion. Modine, the closest cooling comparable, discloses no backlog but did disclose a $165.0 million up-front deposit from one datacenter customer against more than $4 billion of 2027 to 2029 chiller sales.
Source: Open Factory Book-to-Bill League Table (compiled from Q2 2026 earnings releases and SEC 8-K exhibits; as of August 2026)
Seven peers with a printable ratio sit between 1.20x and 2.10x, Powell alone is at 3.0x on a $934 million order quarter, and Vertiv’s own six disclosed quarters before the spike average 1.37x.
Peer backlog growth of 43% to 70% year over year, applied to Vertiv’s $8.5 billion of June 2025, gives $12.2 to $14.5 billion, all of it below the $15.0 billion Vertiv had already reported in December. Vertiv’s Q4 was the outlier in the group, and the peer evidence says the book kept growing in 2026 at a rate closer to the group’s 1.2x to 1.75x than to Vertiv’s 2.9x. Management’s language points the same way: the Q2 2026 release describes “growing pipelines,” the Q2 call described order momentum strengthening globally, and the CEO told CNBC after the 17% share-price drop that “we have very strong backlog supporting that.” None of those is a number.
The Estimate: $16 to $20 Billion at June 30
The arithmetic is the backlog identity, prior backlog plus orders minus sales, run forward from the disclosed $15.0 billion with reported sales of $2,649.5 million in Q1 2026 and $3,274.3 million in Q2. The unknown is orders, set as a book-to-bill in three cases, each stated in assumptions.csv with its source. Low is 1.1x, the floor set by Eaton’s 1.2 rolling ratio and Trane’s 1.23x, with room for the EMEA order softness the CFO described. Mid is 1.4x, Vertiv’s own mean across its six disclosed quarters and inside ABB Electrification’s 1.39x to 1.44x. High is 1.8x, GE Vernova Electrification’s H1 2026 range and well below the 2.9x that management called unrepresentative.
Those cases give $15.6 billion, $17.4 billion and $19.7 billion of backlog at June 30, 2026, or 4.8 to 6.0 quarters of current sales, against 3.0 to 3.9 quarters in every disclosed period before the fourth quarter of 2025. All three imply a deposit ratio of 18% to 23%, above the 2024 to 2025 band and consistent with the “larger advanced payments” the CFO attached to the large orders. A flat backlog at $15.0 billion would require the ratio to have doubled to 24% in six months with no order growth, which no peer’s disclosure supports. The two constraints leave this open: the balance sheet says the book grew, the peers say it did not grow at 2.9x.
For a buyer the ratio to output matters more than the number. At the mid case Vertiv entered July 2026 holding 5.3 quarters of sales in binding purchase orders, up from 3.5 in September 2025. The 10-K says the majority ships within 12 to 18 months, so the queue in front of a new order is longer than anything in the Lead-Time Monitor for Vertiv’s product classes: the Monitor’s published lead time for a static UPS of 500 to 1,500 kVA is 30 to 48 weeks and for a CDU 30 to 50 weeks (Terrapin Construction Group, June 2026), and those are the quotes for a slot that exists. A rack-level power and cooling package for a 2027 hall is competing with $9 to $12 billion of already-booked 2027 deliveries, which is the paid table below.
What to Do Monday
If you need Vertiv UPS, busway, PDU or CDU for an energization date in 2027, place the purchase order or the paid capacity reservation this quarter, and get the factory slot date written into it, not the lead time. Vertiv’s 10-K says the book is binding POs that ship in 12 to 18 months, so a PO signed in December 2026 is a 2028 delivery unless the slot is named. Ask for the deposit percentage in writing and compare it with the 12% to 23% band above and with the deposit line of the Datacenter MEP Cost Table: a vendor asking for 30% is pricing scarcity, and that is a term to negotiate, not a formality. Put the equipment PO dates into the Lead-Time-Adjusted Schedule and see which month the hall actually energizes.
Then calendar two filings. The Q3 2026 10-Q, due in late October, prints the September 30 deferred revenue; at the mid case’s 21% deposit ratio, ~$3.3 billion reads low, ~$3.9 billion mid and ~$4.8 billion high (our arithmetic). The FY2026 10-K, due in February 2027, prints the December 31 backlog, the one number Vertiv has committed to keep publishing. Our 800 VDC piece is the other reason to fix slots rather than sign a five-year frame: downstream SKUs change in 2027.
Behind the paywall: the quarter-by-quarter estimate table through December 2026 with orders, backlog, coverage and implied deposit ratio in each case, and the 2027 slot math, which shows that at the mid case Vertiv ends 2026 with $20.6 billion of binding orders against ~$16.8 billion of 2027 output, so 2027 is allocated before it starts. The full series is in the Lead-Time Monitor.