By Bernardo Campelo, Forbes Business Council E-Commerce Leader, Amazon SPN Certified provider, Amazon SP-API authorized partner, and Founder of PrepVia.
A buyer messaged me last week with a screenshot from a private FBA seller forum. Someone doing real volume, the kind of account that moves pallets, not boxes, had posted a simple question: "Can I see a sample invoice before I sign anything." Thirty replies followed, and almost every one said some version of the same thing. Ask for the invoice first. The quoted rate is never the number you actually pay.
That thread is not an outlier. Every prep center advertises a headline number, a price per unit that looks clean on a comparison spreadsheet. Then the first real invoice arrives and it has nine lines instead of one, and the total per unit looks nothing like the number on the website. The seller is not being overcharged in most cases. The seller simply never saw the full invoice until the goods were already sitting in someone else's warehouse.
So this is that invoice. Not a price list, a real model invoice, line by line, for a single shipment, so you know exactly what belongs on it, what each line actually pays for, and where the cost that never made it into the quote tends to hide.
The 60-second version
The per-unit price on a 3PL quote is one line of a nine-line invoice, not the whole bill. A complete invoice separates receiving, prep labor, materials, storage, outbound handling, and accessorials into distinct charges, and the gap between the quoted rate and the fully loaded landed cost usually lives in the last two categories. Ask for a sample invoice on a shipment close to your own size and SKU mix before you sign anything, because a rate card without a worked example is a promise, not a number.
Why the Quoted Price Is Never the Invoiced Price
A prep center quote almost always leads with one number: a per-unit prep rate, sometimes bundled with a headline receiving fee. That number is real, and it is usually accurate for the work it describes. The problem is what it does not describe. Receiving, storage, outbound handling, and the accessorial charges that show up when a shipment does not go perfectly are rarely part of the quoted figure, because they depend on your carton count, your dwell time, and how your SKUs are packed when they arrive.
We wrote separately about what 2026 market rates actually look like line by line, which is the reference point for what each category should cost. This piece is the other half of that question. It is not about what the market charges. It is about what a real invoice contains, so you know what you are reading when one lands in your inbox.
The gap between quote and invoice is not usually fraud. It is omission, and omission is exactly what a sample invoice fixes, because a sample invoice cannot omit a line that a real shipment actually generated.
The Sample Invoice, Line by Line
Here is a model invoice for a mid-size shipment: 500 units, packed 25 units to a carton, 20 cartons on one pallet, going to a single Amazon fulfillment center as a small parcel plan. The unit is a 10 by 6 by 4 inch item at 1.2 pounds, needing FNSKU labeling, a poly bag, and 30 days of storage before the outbound ship date. The labeling, poly bagging, and storage lines below match PrepVia’s published rates exactly. Receiving, outbound, and the accessorial lines vary by facility and by volume, so treat those as representative market figures to confirm with your own vendor, not a fixed quote.
| Line item | Basis | Rate | Quantity | Line total |
|---|---|---|---|---|
| Receiving | Per pallet | $35.00 | 1 pallet | $35.00 |
| FNSKU labeling | Per unit | $0.40 | 500 units | $200.00 |
| Poly bagging | Per unit | $0.30 | 500 units | $150.00 |
| Storage | Per cubic foot, per day | $0.07 | 7.5 cu ft × 30 days | $15.75 |
| Outbound and loading | Per pallet | $18.00 | 1 pallet | $18.00 |
| 100 percent unit count | Per unit | $0.03 | 500 units | $15.00 |
| Receiving photo documentation | Per shipment | $10.00 | 1 shipment | $10.00 |
Seven lines, and none of them is the headline prep rate you saw on the quote page. That rate was the labeling line, $0.40 a unit, exactly as advertised. Everything above and below it is a separate charge that a per-unit quote alone cannot tell you about, because a quote is a rate and an invoice is what the rate did to a real shipment.
Receiving: Per Carton or Per Pallet, and It Changes the Math
Receiving is the first line on almost every invoice, and it is billed one of two ways. Some prep centers charge per carton opened and counted. Others charge per pallet received, regardless of how many cartons sit on it. Neither method is wrong, but they produce very different bills depending on how you pack.
| Per carton | Per pallet | |
|---|---|---|
| Rewards | Loose or low-carton shipments | Dense, fully palletized shipments |
| Penalizes | Many small cartons on one pallet | A single carton shipped alone, off pallet |
| What to ask | Rate per carton, and whether a minimum applies | Rate per pallet, and the maximum carton count it assumes |
A 20-carton pallet at $35.00 flat costs $1.75 a carton to receive. The same 20 cartons at $2.50 each would cost $50.00, nearly 43 percent more, for identical freight. Neither number is dishonest on its own. The point is that you cannot compare two prep centers on receiving cost until you know which method each one uses and you run your own carton count through both.
Prep Per Unit: What the Labeling Line Actually Covers
FNSKU labeling is usually the cleanest line on the invoice, because it maps to one unambiguous task: printing the barcode Amazon requires, applying it to the unit, and confirming it covers or replaces the manufacturer barcode where Amazon requires that. PrepVia publishes this rate at $0.40 per unit, and it is the one line most sellers already understand before the invoice arrives, because it is the number every quote leads with.
What sellers miss is that the labeling line only covers labeling. It does not include the poly bag the label sometimes goes on, it does not include shrink wrap for a multi-unit set, and it does not include an expiration date sticker if your category requires one. Those are the next lines, and on a shipment with several prep requirements stacked, the labeling charge can end up being the smallest line on the page, not the largest.
Materials: Polybag, Shrink, and Expiration Label Are Three Separate Lines
Materials get folded into "prep" in casual conversation, but a transparent invoice never folds them into one number, because each one is a different task with a different cost. PrepVia prices these individually: poly bagging at $0.30 per unit, shrink wrap at $0.35 per unit, and an expiration date label at $0.40 per unit. A single unit that needs all three, common for a multi-piece set with a shelf life, carries $1.05 in materials before labeling is even counted.
Why Separating These Lines Protects You
When materials are itemized, you can see exactly which requirement is driving the cost. A supplement that needs an expiration label is a different cost profile than a toy that needs a poly bag for suffocation warning compliance, and a bundled kit that needs shrink wrap to stay together in transit is a third profile again. If an invoice shows one flat "prep" number covering all of it, you cannot tell which requirement to drop, negotiate, or fix at the source to bring the total down. Line-item materials are not just for verifying the bill. They are the tool you use to find your own savings.
Storage: Billed by the Cubic Foot, by the Day
Storage is the line that looks smallest on a single invoice and becomes one of the largest over a full quarter, because it compounds with time rather than with units. PrepVia bills storage at $0.07 per cubic foot per day. A pallet holding 500 units at 7.5 cubic feet of total volume costs $0.525 a day to store, which is trivial for a week and materially different for two months.
The number that actually matters is not the daily rate. It is your dwell time, meaning the days between when a shipment is received and when it ships out to Amazon. A seller who turns inventory in ten days pays a fraction of what a seller who lets pallets sit for sixty days pays, on the exact same rate card. Ask for the storage rate, and then separately ask what the prep center's average dwell time actually runs, because a low storage rate on a facility with slow turnaround can cost more than a higher rate on a fast one.
Outbound and Loading: The Line Most Buyers Forget to Ask About
Receiving gets attention because it is the first line on the invoice. Outbound and loading, the charge for building the final pallet, wrapping it, staging it, and loading the dock for the carrier, gets far less scrutiny, and it should not, because it is a real labor line on every shipment that leaves the building. In the model invoice above it runs $18.00 for one pallet, a small number on its own, that scales the same way receiving does when a shipment splits into multiple pallets or multiple partial shipments under Amazon's placement rules.
The line to watch is not the base outbound rate. It is what happens when your shipment plan goes to more than one destination. For a standard size unit like the one in this model, Send to Amazon offers two placement options: minimal splits, usually one location for a per-unit placement fee, or Amazon-optimized splits, five or more locations with no placement fee but at least five identical cartons per item. The two or three location partial split exists only for bulky items. An optimized plan can mean five or more separate outbound charges where the quote assumed one. That is a fee that a per-unit prep quote almost never surfaces, because it depends on the placement option chosen on Amazon's side of the process, not on the prep center.
24 to 36h prep. 35-hour end-to-end guarantee or the prep is free. Net-30 terms. From 50 units to full truckloads.
Accessorials: Where the Real Surprises Live
Accessorials are the catch-all category for work outside the standard prep flow, and they are where a clean-looking quote turns into an invoice nobody predicted. The most common ones are a 100 percent unit count, photo documentation on receiving, disposal of damaged or rejected units, and processing returned inventory sent back to the facility.
The Four That Show Up Most Often
A 100 percent unit count, as opposed to a sample count, exists because a shipment with a declared quantity that does not match the received quantity creates a problem for you at Amazon long before it becomes a problem for the prep center. Photo documentation on receiving exists for the same reason we cover in what belongs in a prep center agreement: it is your only independent record if Amazon later reports a shortage. Disposal charges apply to units that fail inspection or arrive damaged, and returns processing applies to inventory Amazon sends back, which needs its own receiving and count cycle exactly like new inbound freight.
None of these charges is unreasonable on its own. A shipment that arrives short needs a count, a shortage claim needs a photo, and a damaged unit needs somewhere to go. The problem is not the existence of accessorials. It is a quote that never mentions them, next to an invoice where they are the majority of the surprise.
How to Ask for a Sample Invoice Before You Sign
The forum thread that started this piece had the right instinct. A sample invoice, run on a shipment close to your own size and SKU mix, tells you more in five minutes than a rate card tells you in an hour, because a rate card is a promise and an invoice is a record of what actually happened. Before you sign with any prep center, our guide on how to choose a fba prep center covers the broader vetting process, and the invoice request belongs inside that call, not as a separate step afterward.
- Ask for an invoice on a real past shipment, not a hypothetical one. A hypothetical example can omit a line by accident. A real invoice cannot, because the line already happened.
- Match the shipment to your own profile. Unit count, carton count, and whether the product needs poly bagging, shrink wrap, or an expiration label, because a sample invoice for a different product profile will not surface your own accessorial exposure.
- Count the lines, not just the total. Seven or more separate lines is normal and healthy. A single bundled "prep" line is the sign of an invoice built to be hard to audit.
- Ask what triggers each accessorial charge. A 100 percent count, a photo fee, or a disposal charge should each have a plain-language trigger you can read before the shipment ships, not a definition you learn from the invoice itself.
- Price your own dwell time into storage. The daily rate matters less than how many days your inventory actually sits, so ask for the facility's average turnaround, not just the cubic foot rate.
A prep center that hesitates to share a sample invoice is telling you something. The rate card was built to be quoted. The invoice was built to be paid, and those are not always the same document.
Frequently Asked Questions
What should a 3PL invoice include besides the prep rate?
A complete invoice separates receiving, prep labor, materials such as poly bagging and shrink wrap, storage billed by the cubic foot per day, outbound and loading, and accessorials like unit counts, photo documentation, disposal, and returns processing. If a quote only mentions one per-unit number, ask which of these categories are missing and what triggers them, because the missing lines are usually where the real cost sits.
Why does my invoice total look different from the quoted per-unit price?
The quoted price is almost always the prep or labeling rate alone. The invoice total adds receiving, materials, storage for the days the shipment sat before outbound, loading charges, and any accessorial fees the shipment actually triggered. None of those additions are hidden fees in the fraudulent sense, they are simply charges the headline quote never included, which is why asking for a sample invoice before signing matters more than comparing quoted rates.
What is the difference between per-carton and per-pallet receiving fees?
A per-carton fee charges a set rate for every carton opened and counted, which rewards loose or low-carton shipments and penalizes many small cartons stacked on one pallet. A per-pallet fee charges one flat rate regardless of carton count, which rewards dense, fully palletized freight and penalizes a single carton shipped alone. Run your own carton count through both methods before comparing two prep centers on receiving cost.
What accessorial fees are normal to see on a prep center invoice?
The most common accessorials are a 100 percent unit count when declared and received quantities need reconciling, photo documentation taken at receiving as proof of condition and count, disposal of damaged or rejected units, and processing returns that Amazon sends back to the facility. Each should have a plain-language trigger you can read before the shipment ships, not a definition you only learn from the invoice.
How is 3PL storage actually billed, and why does it matter more than the rate suggests?
Storage is typically billed per cubic foot per day, so the daily rate looks small on any single invoice. The number that actually drives your total cost is dwell time, meaning how many days a shipment sits between receiving and outbound. A low storage rate at a facility with slow turnaround can cost more over a quarter than a higher rate at a facility that ships inventory out quickly, so ask about average dwell time, not just the rate.
What is a fair market price for FNSKU labeling, poly bagging, and shrink wrap?
PrepVia publishes these as separate lines: FNSKU labeling at $0.40 per unit, poly bagging at $0.30 per unit, and shrink wrap at $0.35 per unit, with an expiration date label at $0.40 per unit when a category requires one. Any invoice that bundles all of these into one flat prep charge makes it harder to see which requirement is actually driving your per-unit cost, and harder to find savings without dropping a compliance step you actually need.
How do I ask a prep center for a sample invoice before I sign an agreement?
Request an invoice from a real past shipment, not a hypothetical example, and ask that it match your own unit count, carton count, and prep requirements as closely as possible. Count the number of distinct line items rather than just the total, since seven or more separate lines is normal and a single bundled prep charge is harder to audit. A prep center that resists sharing this before you sign is worth treating as a red flag on its own.
Final Take
The forum question that started this piece was not really about pricing. It was about trust, and a sample invoice is the fastest way to earn it or lose it. A per-unit rate on a landing page costs a prep center nothing to publish, because it describes one task in isolation. An invoice describes what actually happened to a real shipment, with every line a buyer can check against their own operation, and that is a much harder document to fake or dress up.
Every line in the model invoice above exists for a reason. Receiving proves what arrived. Labeling and materials cover what Amazon requires before a unit can sell. Storage prices the space a pallet occupies while it waits. Outbound and loading move it back out the door. Accessorials cover the work that only shows up when something does not go exactly to plan, which on a large enough operation is nearly every shipment eventually.
None of that complexity is a reason to distrust a prep center. It is a reason to insist on seeing it before you sign, not after the first invoice lands. A rate card tells you what a prep center wants to charge. A sample invoice tells you what a prep center actually charges, and the gap between those two documents is the single most useful thing you can learn before committing a quarter of inventory to a new facility.
If your next question is whether that gap holds true across a full year and not just one shipment, that is exactly what true profit per ASIN is built to answer, because the fully loaded landed cost from this invoice is one of the inputs that number needs to be real.
Talk to PrepVia about transparent, line-item pricing →
PrepVia is Amazon SPN Certified, prep window 24-36 hours, Net-30 available.
