3PL storage billing methods compared

Storage is the line on a 3PL invoice that causes the most arguments. The client sees a number and wonders how you got there. You look at the same number and wonder whether it covers the space you gave up. The method you pick decides most of that.

This page walks through five common ways to bill storage, shows the same inventory priced under two of them, and ends with questions to settle before you put a method in a contract. All rates below are made-up examples. Replace them with your own costs.

Why the method matters more than the rate

Two 3PLs can quote the same headline rate and still send very different invoices. One bills by the month, the other by the day. A client who ships out half their stock on day ten sees a lower bill from the second and the same bill from the first.

The method also decides how much work your team does. A method that needs a nightly count of every pallet is only practical if your system records those counts for you.

The five methods

1. Per pallet position, per month

You charge a flat monthly rate for each pallet position the client uses. It is easy to explain and easy to invoice.

The weak spot is timing. You must decide what counts as "used": any pallet present during the month, the count on the first day, the count on the last day, or the highest count reached. Each rule gives a different bill, and the client will notice.

Best fit: steady inventory where the pallet count barely changes.

2. Per pallet, per day (pallet-days)

Each day you count the pallets in storage for a client, add up the daily counts over the month, and multiply by a daily rate. A pallet that sits for six days is charged for six days.

This matches the bill to the space actually used. It is also the method that most needs system support, because somebody has to capture a daily count without it turning into a chore.

Best fit: clients with seasonal or lumpy inventory who will push back on paying for a full month of space they used for a week.

3. Per cubic foot or cubic metre

You charge for the volume the goods occupy. This works when products are small or oddly shaped and do not fill a pallet position neatly. It needs reliable item dimensions on file. If dimensions are wrong, the bill is wrong.

Best fit: shelved or bin-stored goods where a pallet is not the natural unit.

4. Per square foot of floor

You charge for the floor area a client holds, often by a reserved zone. It suits clients who want a dedicated block of space and are happy to pay for it whether it is full or not.

The risk is on your side: if the zone sits half empty, you still bill the same amount, and the client may start asking whether they can give some of it back.

Best fit: floor-stacked or bulky goods, or dedicated zones.

5. Per location or bin, per month

You charge for each shelf, bin or rack location a client occupies. It is common for small-parts storage. The bill moves with the number of locations, so a tidy client who consolidates stock pays less, and a client who scatters one carton per bin pays more.

Best fit: pick-face and shelf storage with many small SKUs.

One inventory, two methods

Here is a hypothetical example. A client sends in 30 pallets of seasonal goods on day 25 of a 30 day month. Before that they had nothing with you.

Method 1, charging a full month for any pallet present: 30 pallets at an example $15.00 each is $450.00.
Method 2, pallet-days at an example $0.50 per pallet per day: the 30 pallets are present for 6 days (days 25 to 30), so 30 x 6 = 180 pallet-days, and 180 x $0.50 = $90.00.

Same goods, same building, $360.00 apart. Neither is wrong. They answer different questions. The first says "this space is reserved for the month once you arrive". The second says "you pay for what you actually hold, day by day". Which one you use should be in the contract, not decided at invoice time.

Notice the example rates were chosen so a full 30 days under method 2 equals $15.00 per pallet. That is a sensible check when you offer both: a pallet stored all month should cost about the same either way, and the difference only shows up when inventory moves.

Rules you need to settle for any method

Whatever method you choose, write down:

The counting point. When is the count taken? Midnight, end of shift, or the system's daily snapshot?
Partial pallets. Is a half pallet charged as one position? What about a pallet split across two locations?
Mixed pallets. If a client's goods share a pallet with another client's, who pays for the position?
Minimum charge. Is there a floor per month, so a client with one pallet still covers the cost of being set up?
First and last period. Is the month of arrival prorated? Is the month of departure?
Billing cycle. Calendar month, or from the client's start date each month (anniversary billing)? Anniversary billing spreads your invoicing work through the month but complicates reporting.

If any of these is left open, you will settle it case by case, and clients will remember the cases that went against them.

Checking your system can support the method

Before you promise a method, check it with a small test. Pick one client with a known history. Work out the storage charge by hand, then see whether your system produces the same figure. If it cannot, you have found a gap before a client did.

Ask these questions of any billing tool or process:

Can it take a daily snapshot of quantity by client and by location?
Does it handle items moved between locations without double counting?
Can you override a figure and see who changed it and why?
Can a client see the count behind the charge?

That last point is worth more than it looks. Disputes get short when the client can open the same numbers you used.

Which should you pick?

If most clients hold steady inventory, per pallet per month is simple and fine. If your clients' stock swings, pallet-days is fairer and tends to cost you fewer arguments, at the price of needing good records. Per location suits shelf storage. Cubic and square measures suit special cases.

You can also mix them: pallet-days for pallet storage, per location for the shelf area, and a monthly minimum across the account. Mixing is fine as long as each charge on the invoice names its own unit.

Next step

Take your three largest clients and price last month under two methods. The gap between the two totals tells you which clients would notice a change, and which methods deserve a closer look.