# Why your freight costs rise even though rates were locked > Locked rates but rising cost is tender leakage — rejected loads, off-contract lanes, spot fill, surcharges. Where it hides (SKU × lane × month), why invoices lag, and what a leading tail-risk indicator looks like. - Type: Article · Jul 2026 · 6 pages · 6 min read - Author: Adam Karpiński, Synlogica - Canonical: https://synlogica.ai/resources/why-freight-costs-rise/ ## 1. The short answer Your freight rates can be locked in an annual tender and your freight *costs* can still rise — because the awarded rate is only the price of the lanes that are actually used at that rate. **Tender leakage** is the gap between the tendered rate and what you really pay once volume drifts to non-awarded lanes, carriers decline loads, spot freight fills gaps, and accessorials and fuel surcharges accumulate. The rate held; the cost leaked around it. **Bottom line** A locked rate protects one cell of a large matrix. Cost leaks through the cells the tender didn't cover: rejected loads, off-contract lanes, seasonal spot exposure, surcharges. You only see it when invoices reconcile — months late. ## 2. What tender leakage actually is An annual freight tender awards a rate per lane to a carrier at an assumed volume. Reality then diverges from the assumption in several ways, each of which quietly raises the effective cost: - **Load rejection** — the awarded carrier declines when capacity is tight, and the load goes to the next carrier at a higher rate, or to spot. - **Volume drift** — production and demand move volume onto lanes that were lightly tendered or not tendered at all. - **Spot exposure** — gaps are filled at the prevailing spot rate, which is volatile and usually higher. - **Accessorials & surcharges** — detention, redelivery, fuel and mode-specific surcharges land on the invoice, outside the headline rate. None of these breaks the tender. Each one leaks cost past it. ## 3. Where the money hides — SKU × lane × month Leakage is invisible at the aggregate. Total freight spend can look on-budget while specific **SKU × lane × month** cells run far over — and those cells are where the intervention is. A useful diagnostic asks, per cell: what share of volume actually moved at the awarded rate, and what did the rest cost? | Lane | Awarded volume | Actual at rate | Effective overspend | | | Cold-chain A → B (peak month) | 100% | 62% | High — spot filled 38% | | | Ambient C → D | 100% | 96% | Low | | | Cold-chain B → E (new SKU) | lightly tendered | — | High — mostly off-contract | | *Illustrative pattern.* The lesson holds: a handful of cells — often peak-season cold-chain lanes and newly ramped SKUs — carry most of the leakage. Find those, and you have found the freight budget's tail risk. ## 4. Why invoices are a lagging indicator By the time freight invoices reconcile, the exposure is history — the loads have moved, the spot rates were paid, the quarter is closing. Invoice reconciliation tells you what leaked; it cannot stop it. That is the structural problem: the only signal most teams have arrives after the money is already spent. ## 5. What a leading indicator looks like A leading indicator scores **tail-risk per lane before the exposure lands** — combining awarded-volume coverage, historical rejection rates, demand volatility per temperature class, and current spot-rate pressure. It surfaces the small set of lanes most likely to leak next quarter and recommends a targeted mini-tender for them *before* invoices reconcile. This is what [Synlogica Terminus](https://synlogica.ai/) Transport (Terminus M1) does: it measures leakage across SKU × lane × month, scores lanes by tail-risk, and produces a governed recommendation — with the input-data lineage so the number is auditable. The full method is in the [tender-leakage white paper](https://synlogica.ai/resources/tender-leakage/). ## 6. FAQ ### If our rates are locked, how can freight cost rise? Because the locked rate only applies to volume that actually moves at that rate. Rejected loads, off-contract lanes, spot fill and surcharges all raise the effective cost without touching the tendered rate. ### Why not just tender more lanes? Over-tendering ties up volume commitments and carrier goodwill on lanes that may not need it, and still can't cover volatility. Targeted mini-tenders on the specific high-leakage lanes are usually cheaper than re-tendering everything — the trick is knowing which lanes those are before the quarter. ### How is leakage measured defensibly? By reconstructing actual cost per SKU × lane × month against the awarded rate, with the data lineage recorded, so procurement and finance can replay the number rather than argue over a gut estimate. ## 7. References - Standard freight-procurement practice: annual RFP/tender award vs realized cost reconciliation. - Market rate benchmarks: ICIS, Fastmarkets, Argus (fuel and accessorial baselines). - EU GDP (2013/C 343/01), Chapter 9 — transportation controls for temperature-sensitive freight.