3PL client onboarding, from contract to go-live
A practical 3PL client onboarding checklist: scope, SKU data and units of measure, labeling, ASNs, opening stock, order integration, returns and test orders.
Many of the problems a 3PL has with a client in the first three months start during onboarding: a missing case quantity, an unagreed returns rule, an order feed nobody tested. This guide is a working checklist for bringing a new client live, in the order the work actually happens, with the questions to ask and the decisions to write down at each step.
The 3PL client onboarding checklist at a glance
Onboarding has two outputs: a signed-off operating agreement and a warehouse system that already knows the client's products, stock and order channels before the first truck arrives. Treat it as a project with an owner on each side, a target go-live date and a short list of gates that must pass before orders flow.
For a straightforward e-commerce client with a few hundred SKUs, three to six weeks is a realistic plan. A B2B client with lot-controlled goods, retailer labeling rules and an ERP integration takes longer. Set the date by working back from the first inbound, not forward from the contract signature.
- Commercial scope, service levels and billable activities agreed in writing
- SKU master data complete: units of measure, pack hierarchy, barcodes, dimensions, weights, tracking flags
- Labeling and packaging rules documented, with photos of good and bad examples
- Inbound booking process, ASN format and first receipt planned
- Opening stock counted, loaded and reconciled with the client
- Order channel connected and tested: API, CSV or manual entry
- Returns authorization, grading and disposition rules signed off
- Reports, billing data and escalation contacts confirmed
- Go-live test orders shipped and checked end to end
Define commercial scope and service levels
Start with what you are and are not doing for the client. Storage type (ambient, chilled, bulk pallet, shelving), receiving method (floor-loaded containers or palletized), outbound mix (parcel, pallet freight, retail replenishment), value-added services and returns handling all change how you set up the operation and what you charge.
Service levels need numbers and cut-offs, not adjectives. "Orders received by 14:00 ship the same day" is testable. "Fast dispatch" is not. Agree how long receiving has from truck arrival to stock being available, what happens to orders that arrive with no stock, and which days and hours the service runs.
Write down every billable activity at the same time, because each one needs a record the warehouse system can count: pallets stored per week, lines picked, units packed, cartons shipped, labels applied, returns processed. If an activity is not captured as a transaction, you will end up estimating it on the invoice.
- Services in scope and explicitly out of scope
- Order cut-off time and ship-same-day rule per channel
- Receiving turnaround target and how it is measured
- Handling for backorders, short shipments and damaged stock
- Billable activities and the transaction that proves each one
Collect SKU data and units of measure
Incomplete item data causes trouble at every later step. Send the client a template with required fields and refuse to load it until it passes validation. At minimum you need the SKU code, description, barcode for each pack level, weight and dimensions, and flags for lot, expiry and serial tracking.
The pack hierarchy matters as much as the SKU itself. For example, an olive oil SKU OIL-008 might be sold as a single bottle, shipped by the supplier in cases of 12, and received on pallets of 60 cases. If you only load the bottle, receivers will count 720 bottles by hand or guess. Get a barcode and a quantity for every unit of measure the client's goods arrive or ship in.
Ask about the awkward cases up front. Does the client's retail customer order under its own part numbers? Can a product only be sold in multiples of six? Are there bundles that ship as one SKU but are picked as components? Does anything need to ship before a certain shelf life remaining? Each answer is a setting to configure before go-live, not a surprise on day three.
- SKU code, description, variant attributes (size, color, flavor)
- Barcode per pack level: each, inner, case, pallet
- Weight in grams and dimensions in millimeters per pack level
- Lot, expiry and serial tracking flags, plus minimum remaining shelf life for dispatch
- Customer item codes, sales multiples and bundle definitions
Agree labeling and packaging requirements
Decide who labels what before goods arrive. If the client's products carry retail barcodes, confirm they scan. If they do not, agree whether you will apply internal barcode labels at receiving, who pays for that, and what the label contains. Our guide to warehouse barcode labels covers the formats and the trade-offs.
Outbound packaging rules are just as specific. Record the carton types allowed, void fill, inserts or marketing leaflets, gift notes, whether products can ship in their own container, and any retailer rules for carton and pallet labels. Photographs of a correctly packed order save more arguments than a written spec.
For B2B clients, ask for each large customer's routing guide. Retail and distribution buyers often specify pallet height, label position, advance notice and delivery booking rules, and a breach can mean a chargeback to your client and a difficult conversation for you.
Plan inbound appointments, ASNs and opening stock
Agree how the client books deliveries: lead time for a dock appointment, which days you receive, and what happens to an unbooked truck. Require an advance shipping notice for every inbound, listing SKU, quantity and, where relevant, lot and expiry. Receiving against an ASN turns counting into checking and makes over, short and damaged variances visible on the day.
Opening stock usually arrives one of two ways. If the client is moving from another warehouse, stock comes in as a large inbound with an ASN built from the old provider's balance. If you are taking over a client's own stockroom, you count it in place. Either way, load it as a controlled, validated import, then reconcile your totals against the client's figures by SKU and lot before you accept responsibility for the balance.
Get sign-off on that reconciliation in writing. Every later discrepancy will be measured against the opening position, and a 3PL that starts with an unverified number owns every gap from then on.
- Booking lead time, receiving days and rules for unbooked arrivals
- ASN format and delivery method (file, API or entered by the client)
- Tolerance for over and short deliveries, and who approves exceptions
- Receive-to-quarantine rule for damaged or short-dated goods
- Opening stock reconciliation by SKU and lot, signed off by both sides
Connect order channels: API, CSV or manual entry
Choose the integration by volume and by who owns the order system. A client running its own storefront or ERP with a developer should post orders by API and receive status updates back. A client with a handful of B2B orders a day can upload a CSV. Very low volume can be keyed in, but manual entry should never be the plan for a client expecting to grow.
Map fields line by line: order reference, ship-to address, service level, line SKUs and quantities, requested ship date, and any lot or expiry constraints for B2B customers. Agree how duplicates are prevented, because a retried request that creates a second order is a double shipment. Look for an API with idempotency keys and webhooks so retries are safe and the client's system hears about dispatch without polling.
Test edits and cancellations, not just new orders. Clients change addresses and quantities after submission, and the question is always whether the change arrived before picking started.
Set returns rules before the first return arrives
Returns start arriving a week or two after the first orders ship, and without rules your team will make them up. Agree who authorizes a return, whether unauthorized returns are accepted, how units are graded, and what happens to each grade: back to available stock, rework, quarantine, return to the client or disposal.
Be specific about sealed and opened goods, missing accessories, and products with expiry dates. A returned serum with an intact seal and eight months of shelf life is sellable. The same serum with a broken seal is not. Write the rule once and the floor can apply it consistently. The returns management process guide walks through grading and dispositions in detail.
Agree reporting and billing data
Ask the client which numbers they will judge you on, then make sure you can report them from system data rather than a spreadsheet someone updates. Typical asks are stock on hand by SKU and lot, receipts, dispatches, on-time shipping against the cut-off, open backorders and returns by reason.
Decide the delivery method and frequency: a daily stock file, a weekly service report, dispatch notifications per order. Name the people on both sides who receive them and who to call when something is wrong, including out-of-hours contacts for peak periods.
Billing uses the same data. Confirm how each billable activity is counted, the invoice period, and how disputed charges are handled. A client who can see the transactions behind a charge rarely disputes it.
Run go-live test orders
Before real orders flow, push a set of test orders through the live setup, using the real integration, real products and real labels. Ship them to an address you control or cancel them after packing, but take every one through each step so you find the gaps while the stakes are low.
Check the outputs, not just that nothing errored. Did the packing slip show the client's branding? Did the dispatch status reach the client's system? Did the lot-controlled order allocate the earliest expiry? Fix what fails, rerun it, and only then agree the go-live date. Plan a hypercare period of one to two weeks with a daily check-in call.
- Single-line and multi-line orders
- An order for a lot- or expiry-controlled SKU
- A bundle or kit, if the client sells them
- An order with insufficient stock to test backorder handling
- An address edit and a cancellation after picking
- A B2B order with pallet and carton labels
- A return received, graded and dispositioned
How NextStock handles client onboarding
In NextStock every stock, order and inbound record carries its owner, so a new client is a new owner in the same warehouse rather than a separate system. You can load the catalog, opening stock, orders, ASNs and purchase orders through staged imports with mapping templates, validation and a preview before commit, and revert an import that went wrong. Products support a pack hierarchy with a barcode per pack, customer item codes, sales multiples and bundles.
Clients can send orders by the REST API (with idempotency keys and webhooks), by CSV, or you can enter them in the office app. Receipt and dispatch emails and scheduled KPI reports keep the client informed. Returns run through RMAs with unit-level grading. A client portal and automated storage and handling billing are on the roadmap and not available yet, so today you share reports and exports instead. See multi-client 3PL support for detail.
A practical NextStock guide. Adapt it to your operation and validate with your team.