How to onboard a new 3PL client without building in errors

Direct answer

A 3PL onboards a client well by settling the operational decisions in writing before any stock moves: what the client's products are and how they are identified, how inbound will be announced, what the service levels are, which billable events exist and who at the client can see and do what. Then it proves the setup with test shipments before go-live. Onboarding sets the account's error rate because bad master data and vague rules get copied into every later transaction.

This page is a workflow guide. It treats billing rules as decisions to record, not as a billing engine; no billing-engine capability is claimed. In LATYNEX's WMS approach, multi-client stock ownership is a described fit and engagements are implementation-led, with capabilities confirmed per project.

Data intake

Collect everything in a structured form rather than through scattered emails. A single onboarding pack, completed by the client and checked by your team, gives you a record of what was agreed and by whom.

• Client contacts by role: operations, inventory, finance, and an escalation contact
• Product list with the fields you need to receive and ship correctly
• Sales channels or outbound destinations, and any special handling or compliance requirements
• Expected inbound and outbound patterns as the client describes them, treated as assumptions to check, not commitments
• Any existing stock at another location that will be transferred in

SKU master

The SKU master is the foundation, so give it a gate. Define which attributes are mandatory before a product can be received: the client's code, description, unit of measure, dimensions and weight where they matter for storage or shipping, and whether batch, lot, serial or expiry tracking applies. Decide how variants are identified, and whether barcodes already exist or need to be created and labelled.

Import the master in a controlled way: validate the file, review exceptions with the client, then load. Agree who can change master data later and how a change is requested. A client changing a product's pack size mid-flow without notice is a common, avoidable source of stock errors.

ASN rules

Agree how the client announces inbound. State the required lead time, the reference format, the level of detail (pallet, carton or unit) and what happens when goods arrive without notice. Write the tolerance for over and short deliveries and who has authority to accept a mismatch. If the client wants your team to hold unannounced goods until instructions arrive, write that too. The receiving design behind these rules is covered in warehouse receiving process.

Billing rules as decisions

This step is often left for later and then causes disputes. Before go-live, record which events are billable, how each is measured, and who approves exceptions. Examples of categories to decide on include storage, receiving, handling on outbound, returns processing and special services. The commercial terms themselves are for your finance and contract owners; this workflow only makes sure the events are defined and that the operation records what billing will need.

Be honest with yourself about the tooling. A WMS records the events that happened. Turning them into invoices may happen in your accounting system or by a per-project integration where one exists. Do not promise a client automated billing you have not confirmed.

SLA

Define service levels in terms your operation can measure from its own records: how soon after arrival goods are receipted, order cut-off times, how quickly orders are processed after release and how discrepancies are reported. Then confirm that the system or process can actually produce a report against each one. An SLA you cannot measure is a dispute waiting to happen. Also state what is outside your control, such as carrier delays after handover.

Portal access

If the client will see stock and orders, decide the access model up front: which users, which roles, what each may see and do, and how access is added and removed. In a multi-client environment, client isolation is the requirement to test hardest. One client must never see another's stock or orders. See 3PL client portal for what a client-facing view can contain.

• Named users per client, with roles rather than shared logins
• Read-only views versus the ability to submit orders or ASNs
• A defined process for the client to raise queries
• Offboarding steps when a client user leaves

Test shipments and go-live

Prove the setup before real volume. Run at least one realistic inbound and outbound through the whole flow: an ASN, a receipt with a deliberate mismatch, a hold and release, putaway, an order, picking, dispatch and the resulting event record. Check that the client-facing view shows what it should and nothing else. Fix, then repeat the parts that failed.

Go live on a short checklist: master data approved, ASN rules signed off, billing events recorded as decisions, SLA measurable, portal users tested and a named contact on both sides for the first days. Use WMS go-live checklist for the warehouse-wide version. To see whether your operation is ready for a system to carry this, try the WMS readiness assessment.