How to verify 3PL volume tiers and discounts on your invoice

Why tier billing needs its own check#

A missed tier costs the gap between tier rates on all the volume billed at the wrong rate, so the loss grows with volume. An invoice usually shows the rate applied, not the tier, so a rate check can pass a line billed at a card rate your volume didn't earn.

Rates change more often than brands expect, sometimes one line at a time, and the 3PL's billing system can lag the rate card. One billing system's help page says tier pricing is set up per client and, once set, overrides that client's standard pick pricing¹. If a negotiated tier doesn't reach the invoice, see Charging list price instead of negotiated tiers.

What your contract has to say before you can check a tier#

Before you check a tier, find the seven terms below in your contract. Start with the shape: volume tiers can apply in two ways². Under the first, the period's whole qualifying volume is billed at the rate of the tier the total reaches (also called all-units pricing³). Under the second, each band's volume is billed at that band's rate and the amounts are added (also called graduated pricing²). One 3PL-side guide calls these blended and marginal discounting⁴, and sources use "tiered" for either^2,3, so describe the shape in words. Some tier terms are written as a percentage off a fee once volume passes a threshold; the percentage can apply to all the period's volume or only to volume above the threshold.

Tier schedules don't always say which shape applies: a 2008 fulfillment agreement filed with the U.S. Securities and Exchange Commission (SEC) bands orders per month without stating it⁵, as do the storage and pick bands on one fulfillment encyclopedia's example rate card⁶.

A monthly minimum is a separate term. If it counts the fees a tier discounts, a tier saving in a month near the minimum can come back as a shortfall (Verifying minimum-billing calculations). Peak-season rates and escalators can change each tier's rate (Annual price escalators and CPI clauses), and a new tier schedule is a rate change (Outdated rates after a contract change). For tier design, see Tiered and volume-based pricing.

Volume tiers vs. other tiers on a rate card#

This article covers tiers on a 3PL's own fees set by how much you ship, store, receive or spend in a period. Size tiers (bins, over-height pallets), weight or oversize tiers, kitting tiers by component count and B2B order-fee tiers by shipment mode are rate checks (Rate verification: checking every billed rate against your rate card). A 3PL's own carrier earned-discount tier can move with its total volume across clients, not yours alone (Discount tiers, earned incentives and the traps in them).

How to verify a volume tier, step by step#

You can check a tier in a spreadsheet with your contract, your own volume records and every invoice for the period, in seven steps.

1. Write down the tier terms. From the signed card or amendment in effect, list the thresholds, rates or percentages, fees covered, period, shape, boundary wording, delivery and exclusions. List any term the contract leaves silent and ask the 3PL for it in writing.

2. Count your qualifying volume for the measurement period from your own records, on the contract's basis and with its exclusions. Orders and packages differ on multi-parcel orders, where one fulfillment is packed in two or more boxes and bills one order fee. A true split, fulfilled across days or warehouses, customarily bills an order fee on each part, so ask whether it counts toward the tier once or per part. Units, picks and lines differ on multi-unit orders; pallets stored depend on the count method. A volume report from the 3PL comes from the same records as its invoice, so it's a tie-out, not an independent check. One 3PL-side guide notes that operations, the client and finance can each hold a different count¹¹. For the count itself, see Matching billed orders to shipped orders or Verifying storage counts against inventory snapshots.

3. Find the tier reached using the contract's boundary wording. If the tier is set from an earlier period, use that period's volume.

4. Recompute the expected charge with the contract's shape. If the shape is unstated, compute both to size the range.

   All volume at the tier reached: expected charge = total qualifying volume × rate of the tier reached

   Only volume above each threshold: expected charge = sum over tiers of (volume inside that tier × that tier's rate)

   Percentage discount: expected charge = undiscounted charge × (1 − discount %), on the fees it covers

5. Compare with what was billed on every line the tier covers, across every invoice in the period, weekly or semi-monthly invoices included, plus any discount line or credit:

   Billed rate = line amount ÷ billed quantity

6. Size the difference in both directions:

   Dollar impact = (billed total for the covered fees − discount lines and credits) − expected charge

   A negative result means you were billed less than the contract supports, such as a tier your volume didn't earn.

7. Log what can't be settled yet, such as a credit not yet due, a period that hasn't closed or volume the 3PL counts differently, and note when each invoice's window closes. Raise the rest in writing inside your dispute window (How to dispute a 3PL invoice: process and etiquette).

When the tier period and the invoice don't line up#

When invoices are weekly or semi-monthly, check a monthly tier across all of the month's invoices, because no single invoice carries the whole month's volume. With weekly invoices, ask whether the 3PL bills a provisional rate and corrects it after the month⁶, or applies the tier from the next month⁴. Under the 2008 SEC-filed agreement, the 3PL invoices "bi-monthly" against a monthly band, and the agreement doesn't say how they fit⁵.

If your dispute window is shorter than the tier period, agree in writing how the tier settles before the first invoice's window closes: the window usually starts when the invoice carrying the charge lands.

If your discount comes as a credit after the period, note when it's due. If it's missing, raise it in writing as soon as the period closes. Windows can run from about a week to a few months (Dispute windows and what happens if you miss them). See also Tracking disputes and credits to closure and Billing cycles: weekly, semi-monthly and monthly, and what's billed when.

What a checkable tier looks like#

A checkable tier is one you can recompute from documents you hold:

• Tier terms in the signed card or amendment: thresholds, rates, period, shape, what counts and how the discount is delivered.
• The volume counted and the tier applied, on each invoice or a monthly statement. One 3PL-side guide advises 3PLs to "show both the thresholds and the final applied tier"¹¹.
• Credits listed with the period they settle.
• A new card, amendment or written notice, with an effective date, whenever tiers change.
• Time to check: a 30-day dispute window is common and 14 days is short.