Detention, lumper, and TONU enforcement in 2026 — the margin lever brokers are sleeping on

The accessorial conversation in 2026 looks nothing like the one the freight market was having in 2022. Detention rates that ran wild during the post-COVID capacity crisis are back in normal ranges, shippers have tightened the documentation and dispute discipline meaningfully, and the era when carriers could charge what they wanted on dock-time overages is in the rearview. What replaced it is a market where accessorials are real revenue, real cost, and a real margin lever — and the brokers paying attention are clawing back five to fifteen percent of revenue in line items most of the field is still treating as a customer-service issue rather than a revenue stream.

This is the operator-side framing on what detention, lumper, and TONU enforcement actually looks like in a tightened 2026 market, why most brokers are still leaving money on the table, and the audit framework that surfaces the gap inside ninety days.

The three accessorials that move the number

Three accessorials carry the bulk of the broker-side margin opportunity, and they each behave differently in the negotiation and the workflow.

Detention is the per-hour charge after the carrier exceeds a contracted free-time window at the shipper or receiver. The 2026 market standard sits at two hours of free time at each end, with a per-hour charge of $50 to $100 after, often capped at a daily maximum. Detention is the largest of the three in dollar terms for most brokerages, and it’s the line item with the most documentation discipline required to actually collect.

Lumper is the charge for unloading services at the receiver — separate labor brought in to break down the freight off the trailer. Lumper isn’t strictly an accessorial in the traditional sense; it’s a pass-through cost the carrier pays at the dock and bills back to the broker, who bills it to the shipper. The margin opportunity sits in handling speed and documentation cleanliness, not in markup.

TONU — truck ordered not used — is the flat fee paid to the carrier when a shipper books capacity and then cancels before pickup. The 2026 market standard runs $150 to $300 depending on the lane and the carrier relationship, and it’s the accessorial most brokers have the weakest discipline around because the load never actually moves.

The broker’s structural position across all three is the same. The broker collects from the shipper, the broker pays the carrier, the broker keeps the spread when the gap exists. The spread isn’t always meaningful in dollar terms on any single transaction, but the cumulative annual number for a brokerage that runs accessorials correctly is meaningful enough to define whether a thin-margin book is profitable or break-even.

Why most brokers leave money on the table

The reasons brokers under-collect accessorials in 2026 are operational, not strategic. The shippers are mostly willing to pay legitimate accessorials when the documentation supports the claim. The carriers are mostly willing to deliver clean documentation when the broker has a process that captures it. The gap is the brokerage’s own discipline in the middle.

The three failure modes show up consistently:

Documentation discipline is weak. The carrier driver arrives at the dock at a time the shipper’s gate log captures one way, the carrier’s dispatch records capture another way, and the BOL captures a third. When the detention claim goes in two weeks later, the shipper challenges the in-time, the broker doesn’t have a single source of truth to point to, and the claim either gets thrown out or negotiated down to half. The brokers running this correctly are capturing in/out times at the dock through geofence-triggered TMS notifications, photo timestamps from the driver, and EDI feeds from the shipper’s WMS where the integration exists.

No automated trigger when free-time runs out. The carrier sits at the dock past the two-hour window, nobody at the brokerage notices in real time, and the detention claim only surfaces after the load delivers and the carrier files the paperwork. By then the in-time is contested, the receiver doesn’t remember the specifics, and the brokerage is in a weak negotiating position to actually collect. The brokers running this correctly have TMS-integrated detention trackers that fire an alert at the 90-minute mark and again at the two-hour mark, with an operations team that contacts the shipper proactively to flag that the clock has started.

No SOP for the dispute. The shipper challenges the detention claim, the broker’s billing team punts to the operations team, the operations team punts back to billing, and the claim sits in dispute limbo for sixty days before getting written off. The brokers running this correctly have a documented dispute escalation — first response within 48 hours with the documentation, second response within seven days with the supervisor review, third response within fifteen days with the executive escalation if the shipper hasn’t settled.

The cumulative effect of these three failures is a capture rate — accessorials successfully collected from shippers as a percentage of accessorials owed to carriers — that lands in the 50 to 70 percent range at most undisciplined brokerages. The brokerages running the discipline correctly are landing in the 85 to 95 percent range, on the same load mix, with the same shipper and carrier base. The 25-percentage-point gap is real margin.

The technology layer

The 2026 toolkit for accessorial enforcement isn’t exotic, but it is meaningfully better than what was available in 2022. The categories that matter:

TMS-integrated detention trackers. Most modern TMS platforms — McLeod LoadMaster, MercuryGate, Trimble TMW, Revenova, the cloud-native crop — now ship with detention tracking modules that pull dock-arrival times from carrier ELDs or geofence triggers, calculate the running clock against the free-time window, and fire alerts at configurable thresholds. The setup work isn’t trivial — the geofence boundaries need to be defined per shipper location, the free-time windows need to be configured per contract — but the run-rate value once the configuration is dialed in is substantial.

Geofence-triggered dock arrival capture. The cleanest way to establish in-time documentation is a geofence-triggered notification when the carrier’s ELD signal enters the shipper’s facility radius. The timestamp is automatic, it’s tied to a verifiable data source, and the shipper has a harder time contesting it than a carrier’s manual entry. Most ELD providers — Samsara, Motive, Geotab, Verizon Connect — now expose this data via API to the broker’s TMS where the integration exists.

Document workflow tools. The dispute resolution side has gotten meaningfully better with tools that bundle BOL, in/out timestamps, dispatch communications, and any photos into a single shipper-facing packet. The brokers using this correctly are sending the dispute response with the full documentation packet in under 48 hours, which materially shifts the resolution rate compared to the email-and-attach-PDF workflow that was standard three years ago.

The carrier side of the equation

The carrier-side dynamic in 2026 deserves more attention than it gets. Top carriers — and increasingly mid-tier carriers — are choosing which brokers to cover for based on accessorial pay reliability alongside the standard pay program. A broker who reliably pays detention within the same payment cycle as the linehaul, with no adjudication delay and no separate 60-day claims process, is materially easier to dispatch into than a broker who treats detention as a separate workflow that runs on its own timeline.

The mechanic that lets brokers offer this without recycling cash through the operating account is straightforward. Carrier-pay funding programs built for freight brokers can fund the accessorial alongside the linehaul on the same advance cycle, against the shipper receivable that the broker is in the process of collecting. That structural decoupling means the broker doesn’t have to wait for the shipper to settle the detention claim before paying the carrier — the funding advances on the carrier-pay obligation, and the shipper-pay timeline plays out separately. From the carrier’s experience, the detention shows up in the same ACH as the linehaul, on the same timeline as everything else, with no separate claim to chase.

The brokers running this correctly are getting first call on covered capacity at posted rates, even when their headline pay timeline isn’t the most aggressive in the market. The accessorial reliability is a piece of the pay-program perception, and it compounds with the rest of the program in the carrier’s decision about which broker boards to log into.

The contract negotiation

The accessorial enforcement conversation starts at the contract level, not at the operational level. The broker who writes weak accessorial terms into the master shipper contract is locked into the weak terms across every load on that contract until the next renewal, and operational enforcement can’t fix what the contract gave away.

The terms that hold up in 2026 contract negotiations:

Detention at two hours free time at each end, $75 per hour after that with a daily cap at $400 to $600, payable on the same cycle as linehaul without separate adjudication. The shippers that push back on this language are signaling something about how they’re going to behave operationally, and the broker should price the contract accordingly.

Lumper as a documented pass-through at actual cost, billed back within seven days of the receipt, with the original lumper receipt as supporting documentation. Markup on lumper is increasingly contested by sophisticated shippers and isn’t worth the relationship cost in most cases.

TONU at $200 to $250 flat for cancellations within four hours of pickup, billable on the same cycle as a delivered load. The TONU language is the one most brokers under-negotiate because it feels punitive, but a shipper with a pattern of cancellations costs the broker real money on driver dispatch and capacity commitments, and the TONU is the only mechanism to recover it.

The contract language matters because it sets the operational baseline. Once it’s in the master, the operations team works against a clear standard. Without it, every load is a separate negotiation.

The ninety-day audit framework

The exercise that surfaces the actual accessorial gap inside a single quarter:

Week one through four. Pull the last quarter’s accessorial data out of the TMS or accounting system. For each accessorial event, capture three numbers — the amount owed to the carrier, the amount billed to the shipper, and the amount actually collected from the shipper. The ratio of collected-to-billed is the capture rate. The ratio of billed-to-owed is the markup rate. Both numbers should be calculated by accessorial type and by shipper.

Week five through eight. Identify the bottom-quartile shippers by capture rate. These are the shippers where the broker is doing the work to charge accessorials and not getting paid for them. For each, pull the dispute documentation, identify whether the failure was contract language, documentation, or process. Fix the lowest-hanging fruit — usually a documentation workflow change — and re-bill the older claims where the documentation is now clean.

Week nine through twelve. Build the run-rate improvement into the operating budget. A brokerage with $30M in revenue and a 60 percent baseline capture rate on accessorials running 8 percent of revenue is leaving roughly $960K on the table annually. Moving the capture rate to 85 percent recovers $600K of that, against operational cost that’s mostly process discipline rather than headcount. Most brokerages running this audit for the first time discover the run-rate improvement is meaningful enough to justify a dedicated accessorial coordinator role, which then accelerates the capture rate further.

The cash-flow note

The piece worth flagging for any broker treating accessorials as a real revenue stream rather than an afterthought: accessorial revenue funds through the same working-capital structure as the linehaul revenue, and the timing mismatch is the same. The broker pays the carrier on the carrier-pay cycle, collects from the shipper on the shipper-pay cycle, and funds the gap with whatever sits underneath the operating cash. A brokerage that ramps accessorial billing from 60 percent capture to 85 percent capture is ramping a real revenue stream that produces a real working-capital draw, and the broader funding stack for 3PLs needs to be sized to support it.

The brokers who get this wrong are the ones who treat accessorials as bonus revenue that gets paid eventually, fund the underlying carrier-pay obligation out of operating cash, and end the quarter with a cash gap they can’t trace because the accessorial billing cycle and the linehaul billing cycle ran on different rhythms. The brokers who get it right are the ones who integrate accessorial revenue into the working-capital model from day one — treating it as a structural revenue stream with structural cost behavior, not as a margin gift that shows up randomly.

The bottom line

Accessorials in 2026 are 5 to 15 percent of revenue for most brokerages, and 100 percent of the margin gap on lower-rate lanes. The brokerages capturing the full opportunity are running documentation discipline, automated workflow triggers, clean contract language, and an accessorial pay program that funds through the same working-capital structure as the linehaul. The brokerages leaving money on the table aren’t being out-priced on the line items themselves — they’re losing them on weak process discipline. The ninety-day audit surfaces the gap. The operational discipline closes it. The funding structure underneath makes it sustainable.