# What a line missing from the first estimate costs > Shops lose money on work they never bill and time on work they bill late. Both usually start with the first estimate. - URL: https://joinrevv.co/blog/the-cheapest-supplement - Author: Revv Team - Published: 2026-10-11 - Tags: Supplements, Estimating Take a front hit with a pulled rail. The estimate goes in, the insurer approves it, and the car comes apart. Then the frame tech finishes the pull and needs a final measurement that nobody wrote down. From there the shop has two choices. It can write a supplement and wait for an answer, or it can do the measurement and never bill it. The first choice costs time and the second costs money. Both trace back to the same line missing from the first estimate. Some supplements can't be avoided. Hidden damage turns up at teardown, and nobody can estimate a bent bracket they can't see. This post is about the other kind: work the repair procedure called for as soon as the repair was decided. ## The work that never gets billed Many shops take the second choice. In the latest "Who Pays for What?" surveys, 45% of shops said they never ask to be paid for the final measurement.[^measure] 31% never list destructive weld testing.[^weld] About 40% have never itemized the time they spend researching diagnostic trouble codes.[^dtc] **Work shops leave off the bill** (Shop surveys, 2026) - **45%** of shops never ask to be paid for the final measurement - **31%** of shops never list destructive weld testing - **40%** of shops have never itemized time for diagnostic code research *From the “Who Pays for What?” surveys by Collision Advice and CRASH Network. See the notes at the end.* These operations are routine. If the repair includes a structural pull, the OEM procedure tells you a measurement follows. If it includes structural welds, the procedure says whether a test weld is required. The estimator often knows enough to list them before the car is apart. They get left off because nobody had time to look them up. ## The work that gets billed late When the shop does catch the missing line, it pays in hours instead of dollars. Writing a supplement takes 30 to 45 minutes on average, according to FenderBender, and a repair with three of them can take 1.5 to 2.5 hours of an appraiser's time.[^supp] Then the car waits for approval. LaMettry's Collision, a multi-shop operator, checked 100 of its insurance jobs and found an average of 4.2 days between sending the first supplement and hearing back. Its DRP jobs came back in under a day.[^wait] Other shops report far longer waits. "We submit another supplement, and now that starts another 10-14-day clock," Michael Bradshaw of K&M Collision in North Carolina said this year.[^clock] **One supplement round** (Industry figures) - Line found - Leak: 30–45 min to write and finalize the supplement, on average. - Sent - Leak: 4.2 days on average for the insurer’s first reply at one MSO, over 100 jobs. Under one day on its DRP jobs. - Approved *Sources: FenderBender and Autobody News. See the notes at the end.* ## Why the first estimate comes up short A thorough estimate takes far longer than most front offices can give it. Mike Anderson of Collision Advice says a visual estimate typically takes 30 to 45 minutes. A repair plan built from the OEM procedures is a bigger job: at a 2023 CIC meeting, one repair planner described spending a little over five hours on a single plan before any disassembly.[^plan] Few shops can spend five hours on every car, so most estimates land somewhere in between. Often the shop is not even starting from its own estimate. Photo inspections made up 26.4% of repairable appraisals in 2025,[^photo] which means many repairs begin with an insurer's estimate written from pictures by someone who never saw the car. ## A line with its source attached Each line added to the estimate also needs a reason the adjuster can check. For most operations the source is one of three things. The estimating guide's notes on what a labor time includes, which shops call the P-pages, show when an operation is its own line. The OEM repair procedure shows what the manufacturer requires. And when a shop questions a database time, the Database Enhancement Gateway publishes the answer.[^deg] An adjuster can argue with an estimator's judgment. It is harder to argue with the page in the manufacturer's procedure. The same source does a second job later. If a line is cut after the estimate goes out, the reply cites the page that put the line there in the first place. ## Where Revv fits Revv writes a first estimate from damage photos, or checks one you already have from CCC ONE, Mitchell, Audatex or the insurer. It adds the operations that are missing, corrects the lines that are wrong, and shows the P-page, OEM procedure or DEG answer behind each one. You approve every line, and you get the finished estimate as a PDF. The goal is more of the repair on the first estimate, so fewer cars sit waiting on a supplement. Your first estimate check is free. [Send us one estimate](https://joinrevv.co/#estimate). [^measure]: Autobody News, ["Who Pays for What?" survey: nearly half of shops never bill for the final measurement](https://www.autobodynews.com/news/who-pays-for-what-survey-nearly-half-of-shops-never-bill-for-the-final-measurement), August 2026. [^weld]: Repairer Driven News, [More shops billing for destructive weld tests with fewer paid](https://www.repairerdrivennews.com/2026/07/03/more-shops-billing-for-destructive-weld-tests-with-fewer-paid-latest-who-pays-survey-open/), July 2026. 31% of shops never list the procedure, a record low. [^dtc]: Repairer Driven News, [Who Pays for What: 40% of shops not charging for DTC research](https://www.repairerdrivennews.com/2026/01/15/who-pays-for-what-40-of-shops-not-charging-tor-dtc-research/), January 2026. Down from 50% in 2020. [^supp]: FenderBender, [The true cost of collision repair supplements](https://www.fenderbender.com/running-a-shop/finance/article/33028793/the-true-cost-of-collision-repair-supplements), January 2019. [^wait]: Autobody News, [Everyone in the collision repair process has a part in solving problems in handling supplements](https://www.autobodynews.com/news/everyone-in-the-collision-repair-process-has-part-in-solving-problems-in-handling-supplements), June 2023. About three quarters of the 100 jobs were non-DRP. [^clock]: Repairer Driven News, [State Farm claims practices cited as ongoing issue by collision industry](https://www.repairerdrivennews.com/2026/05/01/state-farm-claims-practices-cited-as-ongoing-issue-by-collision-industry/), May 2026. [^plan]: Repairer Driven News, [Estimate vs. repair planning: how to keep customers informed](https://www.repairerdrivennews.com/2023/01/23/estimate-vs-repair-planning-how-to-keep-customers-informed/), January 2023. [^photo]: CCC Intelligent Solutions, [Crash Course 2026](https://www.cccis.com/reports/crash-course-2026), reporting 2025 data. [^deg]: Database Enhancement Gateway guidance for [CCC](https://degweb.org/ccc-motor-pathways) and [Mitchell](https://degweb.org/mitchell). ## Questions ### Why do collision repair estimates need supplements? Some damage only shows at teardown, and no estimate can avoid that. Other supplement lines, such as a final measurement after a structural pull or a weld test after structural welding, come straight from the OEM procedure once the repair is known, and can go on the estimate with it. ### How long does a supplement add to a repair? Writing one takes 30 to 45 minutes on average, FenderBender reports. The wait for approval varies. One multi-shop operator measured an average of 4.2 days to the insurer's first reply across 100 jobs, and shop owners describe much longer waits.