3PL inventory management software tracks stock for several clients in one warehouse. It keeps each client’s stock, handling rules and records apart, gives the operator one accurate count of everything on site, and lets each client check their own stock without ringing the warehouse. Software built for a single business usually breaks at the first step, because it assumes one owner for every pallet.
This guide explains what the software has to do, where 3PL stock most often goes wrong, and what to test before you buy.
The table below sets out the six control points that matter most, what goes wrong without each one, and what to check in a system.
| Control point | What goes wrong without it | What to check in the software |
|---|---|---|
| Owner recorded on every stock record | One client’s stock is allocated to another client’s order | Allocation only draws from the owning client’s stock |
| Client-specific batch and expiry rules | Batch control is applied to packaging that does not need it, or missed where it does | Rules can be set per account and switched off per product |
| Goods in checked against the advance notice | Short or over deliveries are received without anyone noticing | Receipts compare quantities with the expected load, with a route for shorts |
| Damage and hold reasons | Damaged stock is put away and picked | Damaged quantities are received separately and held, with the reason, user and time recorded |
| Routine cycle counts | Errors build up until a full count stops operations | Counts run in small batches, with variances traced back to transactions |
| Client stock visibility | Clients phone the warehouse for stock figures | Clients see their own stock in a portal or a daily report |
What is 3PL inventory management?
3PL inventory management is the control of stock owned by several businesses in the same warehouse. At any moment the operator needs to know which client owns each pallet, how much is there, where it sits, and which rules apply to it.
A single-client warehouse can often run from one stock pool. A 3PL cannot. The same product line might arrive from three clients, each with different batch numbers, shelf-life requirements and hold rules, all stored in the same racking. The software has to keep those differences visible at every step, from the goods-in dock to dispatch.
Mathew Buttar, who works on Clarus implementations and has run warehouses for most of his career, puts the job simply. Stock control is the number one job of anyone managing a warehouse, and most other decisions depend on getting it right.
How do 3PLs keep client stock separate?
3PLs keep client stock separate by recording the owning client against every stock record and enforcing that ownership at put-away, allocation and dispatch. Stock from one client should never be offered to another client’s order, even when both sit in the same rack.
Clarus holds each client’s stock segregated within one warehouse, so inventory, reporting and billing for each client stay isolated. For a 3PL running a multi-client warehouse, that isolation is what lets one site serve many businesses without mixing their records.
Client rules belong on the account, with exceptions by product
The rules that differ between clients are usually batch control, expiry and best-before control, serial capture and hold reasons. The practical way to hold them is at account level, with an override for each product. In Clarus, a flag set on the account switches on batch control screens on the handheld only where a product needs them, and a wrong batch triggers a warning before the picker can continue.
Mathew Buttar’s example is a client with 1,000 products, where 900 need batch control and the other 100 are packaging that nobody needs to track by batch. Turn the flag off at product level for those 100 lines and the batch step never appears for them.
Groups keep incompatible stock apart
Some stock cannot share a rack, whichever client owns it. Mathew Buttar’s example is gluten-free product, which must not sit above non-gluten-free product in racking, because a split pallet would contaminate the stock beneath it. Setting up groups lets the system suggest only locations that suit a given product. Put-away then never offers a space that looks free but breaks a segregation rule. The same grouping can keep one client’s stock away from another’s, provided a 3PL sets the groups up that way.
Goods in is where stock accuracy starts
Most stock errors begin at the dock, because the system only knows what it has been told. Mathew Buttar’s first question on a site visit is whether any inbound information can be obtained, yes or no. The next is whether each pallet has a label, and whether that label can be scanned.
The strongest position is an advance notice that carries a pallet-level identifier. Under GS1 standards, the Serial Shipping Container Code (SSCC) identifies each pallet, as GS1 UK explains. GS1 UK also describes how logistics labels work with advance shipping notices in its guidance on shipper labels. If the notice carries the SSCC plus batch, quantity and product code for each line, one scan of the pallet label can accept all of that data. Mathew Buttar’s example is a lorry with 26 pallets, which needs 26 scans rather than a line-by-line keying session. That only works when the data arrives before the lorry does.
Without an advance notice, the system has less to check against. A blind receipt does not know what should have arrived, so a short delivery will not stop the receipt. A pre-receipt lets the system compare the delivery with what was expected, and a short receipt will not complete until someone deals with the gap. Over-receipt is still possible, so the software needs a route for both overs and shorts.
Damage needs its own handling. Damaged quantities should be received separately, put on hold and released only once they have been repaired or disposed of. The software should record each step against a user and a time.
Stock accuracy comes from counting, not hoping
A system holds an accurate record only if the floor is counted often enough to prove it. Full stock checks are costly. They either stop operations, push work into overtime, or move counting onto a night shift. Mathew Buttar prefers cycle counting, where a sample of locations is counted regularly and the findings are used to judge the rest of the site.
JODA Freight, a 3PL, shows what that discipline can achieve. Its stock accuracy rose from the 90% to 97% range in year one to 99% by year two. Stock takes went from weeks on Excel to one day, and year-end counts take two to three days. Read the JODA Freight story for the detail.
Software cannot make a picker scan honestly. The record shows what was scanned, not what was physically picked. If a picker scans the right location and the right pallet, then takes a box from the pallet beside it, the record is wrong. Scanning narrows that gap but does not close it. Mathew Buttar’s point is that being on the floor matters as much as sitting in front of a screen, and counts are how you check what the scans cannot show. For how a structured count is run, see our guide to structured warehouse stock checks.
How do 3PL clients see their stock levels?
3PL clients see their stock levels through a client portal that shows current stock for their own products, or through a daily stock report sent by email. Both reduce the number of calls to the warehouse for a stock figure. A portal gives a live view, while a report gives a fixed snapshot.
Clarus offers a client self-service portal where clients see real-time stock levels and order status. Mathew Buttar describes the same pattern from implementations: clients can check how much stock they hold, or have a daily stock report emailed to them.
Visibility also explains why stock is on hold. A client can see the reason for a hold and who placed it. Mathew Buttar says that gives the 3PL a frank conversation to have. If a client’s packaging keeps failing on pick, the damage record shows it, and the conversation becomes about packaging rather than blame. The trade body UK Warehousing Association makes a related point in its Warehouse of the Future paper, which says 3PLs need to strike a balance in data sharing with clients, exchanging enough information to be useful while keeping it secure.
Expiry, FIFO and holds
Stock rotation rules are where client differences bite hardest. In Clarus, FIFO means the oldest stock record by creation date, down to the millisecond. First-expiry-first-out is a separate rule that works from sell-by dates and is configured on the account. People often mix the two up, so ask a vendor to show both working on the same product.
UK labelling separates the two kinds of date. Use-by dates relate to safety, and best-before dates relate to quality, as GOV.UK’s guidance on food labelling sets out. A 3PL handling food needs to rotate each product against the right date, and that should not depend on a clipboard.
Bulk storage makes oldest-first hard. The oldest pallet may sit at the back of a stack, and moving fifty pallets to reach it is not practical. Mathew Buttar’s rule is that if you use sell-by dates, you should not bulk stack. Keep stock accessible pallet by pallet.
Holds need a record too. Stock can be set to go on hold automatically when it is put away in a quarantine location. In one example from a 3PL’s own work, a product that needed a veterinary sign-off was placed on hold on receipt, so it could not be allocated until someone released it. Each hold and release should record the reason, who did it and when.
Holds and traceability matter most when something goes wrong. Mathew Buttar describes the recall sequence as finding what was sent, to which customer and on which vehicle, then holding what is left and stopping any pick that has not yet left. That only works if dispatch data was captured at the time. The Food Standards Agency expects food businesses to identify their suppliers and customers quickly when a product has to be withdrawn or recalled, as its food incidents guidance explains. Its longer traceability guidance covers traceability systems in detail.
Billing storage from the stock record
Storage charges are only as defensible as the stock record behind them. In Clarus, transactions are time-stamped and recorded against the person who made them, so a disputed pallet can be traced back through its receipt, moves, holds and dispatch.
The admin side is where the time goes. Before moving to Clarus, the managing director of St John’s Hall Storage spent around four days at the end of each month checking invoices that had been re-keyed from the warehouse system into the accounts package. That re-keying has gone, and invoicing time is down by 90%.
When you evaluate billing, ask the vendor to show a storage charge built from stock records rather than a report typed up from a spreadsheet. Then ask how the charge handles a pallet that moved twice in the same month.
What inventory software will not fix
Software does not repair a weak process. Mathew Buttar’s view is that a system should complement the way a business works, not replace the need to understand it. A WMS will not fix poor master data, inconsistent labels or a receiving team that never asks suppliers for advance information.
Some things happen outside the warehouse system. Once a load leaves the back door, the system does not control what happens on the lorry. Clarus does not offer temperature mapping or a returns module, and its warehouse map is a visual aid rather than an exact digital twin. A 3PL with heavy returns or cold-chain mapping needs those requirements tested before signing up.
How to choose 3PL inventory management software
Test the system against your own client mix, not a demo dataset. These four checks take an afternoon and expose most of the gaps:
- Two clients, two rule sets: set up one client with batch control and another without, then check that allocation never crosses the owner line.
- A short delivery: run a receipt that is short against the advance notice, and check that it stops or flags for action.
- The client view: ask to see exactly what a client sees in the portal, including whether a hold reason is visible to them.
- A recall trace: pick one batch and time how long it takes to list every customer and shipment that received it.
Timescales matter too. A standard Clarus implementation goes live in around 12 weeks, provided the project has the right support on both sides. Complex projects with many features or high volumes take longer. Mathew Buttar’s view is that 12 weeks is a sensible standard because teams need time to learn the new process.
If you run a 3PL, the WMS for 3PL page sets out how Clarus supports that model, and our 3PL logistics WMS page covers the wider warehouse picture. For a broader comparison of options, see our guide to the best 3PL software.
Speak to a warehouse expert
If you’re evaluating your options and want to see how a purpose-built WMS works in practice, Clarus is worth a conversation. We work with 3PLs and distributors across the UK to implement warehouse management software that fits the way you operate, not the other way around.
Get in touch with our team to talk through your requirements.