Switching 3PLs: Inventory Transition and Cutover Plan

The new 3PL went live on a Monday. By Wednesday, customer service had 340 backorders for products the client's ERP said were in stock, the outgoing warehouse said it had shipped everything, and the incoming warehouse said it had received nothing under those item codes. The stock was sitting on two trailers in the new site's yard, unreceived because the transfer notice carried pallet IDs the new WMS had never seen.

A 3PL switch is an inventory move wrapped in a contract exit, and most of the loss happens in the gaps between three ledgers: the outgoing WMS, the incoming WMS and the client's own stock records. A dated plan with named owners, two independent counts and an in-transit location in the client ERP keeps every unit accounted for, usually within a 0.1% transfer tolerance.

• What the plan covers: exit terms to settle first, a twelve-week calendar, exit and receipt counts, in-transit visibility, dual running and the Indian GST paperwork for moving stock.
• What you get to reuse: an owner and evidence table, a transition bridge formula, a worked reconciliation in dollars and rupees, and go-live gates.

Why 3PL exits lose stock between two warehouse ledgers

Stock goes missing in a 3PL switch when no ledger owns it: after the outgoing site ships it and before the incoming site receives it. The fix is to make that state explicit, with its own location, its own owner and an evidence pack for every load.

During normal operation one WMS reports to one client ERP, and a daily reconciliation compares them. During a transition there are two warehouses reporting at once, inbound purchase orders being redirected, customer orders split between sites, and trailers carrying hundreds of pallets between them. Each of those flows needs a defined hand-off and a person who signs it.

Contract terms to settle before notice: lien, data and site access

Settle disputed invoices, data return and access rights before giving notice, because the outgoing provider's bargaining power peaks once it knows the business is leaving. A warehouse holding unpaid charges can lawfully refuse to release goods in the US, and many contracts give the same right elsewhere.

Under the Uniform Commercial Code, section 7-209, a US warehouse has a lien on goods covered by its warehouse receipt or storage agreement for storage, transportation, insurance, labour and related charges. If the receipt or agreement says so, the lien also secures charges owed on other goods. Section 7-209(e) says the warehouse loses the lien on goods it voluntarily delivers, which is exactly why it will not release them while invoices are open.

US warehouse liens under UCC section 7-209 cover storage, handling and related charges and, where the storage agreement states it, charges on other goods; because voluntary delivery ends the lien, a 3PL exit plan should settle or escrow disputed invoices at least 10 business days before the first transfer trailer.

In India, release terms depend mainly on the warehousing agreement's lien, notice and exit clauses, so read them with counsel before notice; this guide does not set out an Indian statutory position. In both markets, check the clauses below.

• Notice and minimum term: confirm the notice period, any minimum volume or space commitment through the exit date, and whether storage minimums continue while stock drains.
• Exit and handling charges: agree the rates for transfer picks, outbound loading and any per-pallet exit fee in writing, so the final invoice cannot introduce them.
• Shrink allowance and liability: note the contractual shrinkage allowance and the valuation basis for claims, because the exit count will test both.
• Data return: require the full transaction history, lot and serial records, and the final stock file in an agreed format, plus read-only system access for 90 days after exit.
• Count observation: secure the right for client staff or an independent counter to observe and test-count the exit inventory.

A twelve-week transition calendar from notice to final release

Twelve weeks is a workable default for a single site with a few thousand SKUs. Compress it and you lose the dual-running window that catches master data errors; stretch it and you pay two providers for longer than you need to.

1. Weeks 1 to 2, notice and commercials: serve notice, settle open invoices, agree exit charges and data return, and name a transition lead on each side.
2. Weeks 3 to 4, new site build: load item, unit-of-measure, lot and customer master data into the incoming WMS; test order, receipt and stock messages end to end.
3. Weeks 5 to 6, inbound redirect: point new purchase orders and supplier ASNs at the new site so it starts filling without any transfer.
4. Weeks 7 to 8, dual running: ship customer orders from both sites by agreed rules and reconcile both sites daily against the client ERP.
5. Week 9, exit count: freeze the outgoing site's remaining stock, count it blind, recount variances and agree the result.
6. Weeks 10 to 11, bulk transfer: move counted stock by sealed trailer with a load list per trailer and receipt within 24 hours of arrival.
7. Week 12, close-out: final invoice, deposit return, written release, data handover and closure of in-transit balances.

Integration testing in weeks 3 and 4 decides most of what follows. Our ERP-WMS integration test cases list the receipt, order and adjustment messages worth proving before any stock moves. If the decision to switch is still open, the own warehouse versus 3PL cost comparison covers the economics.

Exit counts at the outgoing site and receipt counts at the new one

Count twice: once at the outgoing site before anything moves, and once at the incoming site as each trailer is received. The first count settles the outgoing provider's liability; the second isolates loss in transit or in receiving.

The exit count should be blind, with counters entering quantities without seeing the system figure, and every location with a variance above an agreed threshold recounted by a second team. The client's observer test-counts a sample and signs the final variance list. Lot and expiry must be captured, not only quantity, because a correct total with the wrong lot split becomes a recall problem later.

For the count mechanics, such as tag control, team sizing and recount triggers, our wall-to-wall physical inventory guide applies directly. The receipt count at the new site uses the transfer load list as its expected quantity and records seal integrity, pallet IDs and damage before putaway.

A 3PL inventory transition should close with the transfer variance, units shipped by the outgoing warehouse minus units received at the incoming warehouse, at or below 0.1% of units moved, after a blind exit count recorded in the client ERP and a seal-checked receipt within 24 hours of each trailer's arrival.

Keeping in-transit stock visible while trailers move between sites

Create a transit location in the client ERP for each trailer, move stock into it when the outgoing site confirms shipment, and move it out only when the incoming site confirms receipt. Nothing should exist in neither warehouse without appearing somewhere.

The transfer notice must carry identifiers the incoming WMS already knows. If the outgoing site ships pallets under its own licence plate numbers, either load those IDs into the new WMS before arrival or relabel at loading. The incident later in this guide came from skipping that step. The bridge below shows what the client ERP should reconcile to at each stage.

Transition bridge per SKU and lot (all quantities in base units)

Q_received_new = Q_book_freeze
               - V_exit_count
               - Q_shipped_cust
               - Q_in_transit_open
               - V_transfer

Where:
  Q_book_freeze   client ERP balance at the outgoing site when the freeze starts
  V_exit_count    book minus agreed exit count (positive = shortage)
  Q_shipped_cust  customer orders shipped from the old site after the freeze
  Q_in_transit_open  units on trailers not yet receipted at the new site
  V_transfer      units loaded minus units received (positive = shortage)

Tolerance at close-out (Q_in_transit_open must be 0):
  |V_transfer| / units_loaded  <= 0.001
  any single trailer with |V_transfer| > 0 needs a seal record and a cause

Dual running: routing orders and inbound between both warehouses

Dual running works when every order has one site chosen by a written rule before release. Ad hoc splitting by customer service is how orders get picked twice or not at all.

• Inbound first: redirect supplier receipts to the new site from week 5, so the old site only drains and never refills.
• Allocation rule: source each order line from the old site while it holds enough stock for the full line, otherwise from the new site; avoid splitting a line across sites.
• Customer promise: check that both sites can meet the same carrier cutoffs and labelling requirements, or the customer sees two service levels for a month.
• Daily reconciliation: compare each site's stock file to the client ERP every morning; the daily WMS-to-client reconciliation pilot explains how to run that comparison, and this plan applies it to two sites at once.
• Returns routing: point customer returns to the new site from the first day of dual running, so the old site does not receive goods it is about to hand over.

Indian GST paperwork for moving stock between warehouses

Moving goods between two warehouses in India needs a document for the movement and, above ₹50,000 of consignment value, an e-way bill, even where no sale takes place. If the new warehouse is in another state under a different GSTIN, the transfer is itself a taxable supply.

Within one state and one registration, the client moves its own goods without a sale, so it uses a delivery challan under CGST Rule 55. Rule 138(1) requires an e-way bill for consignments above ₹50,000 moved for reasons other than supply. The new warehouse address must also be added to the registration as an additional place of business through FORM GST REG-14, which Rule 19 requires within fifteen days of the change.

Stock moved between an outgoing and an incoming 3PL warehouse under one Indian GSTIN needs a CGST Rule 55 delivery challan and, above ₹50,000 of consignment value, an e-way bill under Rule 138(1)(ii); the new address is added through FORM GST REG-14 within fifteen days under Rule 19.

• Inter-state transfers: branches in different states are distinct persons, and Schedule I, paragraph 2 of the CGST Act treats supplies between them as supplies even without consideration, so the transfer needs a tax invoice and IGST, with credit taken by the receiving registration.
• E-way bill validity: Rule 138(10) gives normal cargo one day for up to 200 km and one more day for each further 200 km, so plan long transfers so trailers do not run out of validity while waiting at the new dock.
• Write-offs: section 17(5)(h) blocks input tax credit on goods lost, stolen, destroyed or written off, so a transition shortage written off in the books also needs a credit reversal.

In the US there is no federal movement document comparable to the e-way bill for a domestic transfer of a client's own goods; the bill of lading and the warehouse receipts carry the evidence. That asymmetry is why Indian transitions need the tax team in the plan from week 1 rather than at close-out.

The cutover weekend that lost 214 cartons, step by step

The trace below is a composite of a common pattern. Each team did its own step correctly; the identifiers did not survive the hand-off between two WMSs.

1. Saturday 06:00: the outgoing site freezes the remaining 214 cartons of fast-moving SKUs after the exit count and builds transfer order TO-88412.
2. Saturday 14:20: trailer TRL-5531 leaves with seal 0448812; the outgoing WMS sends a transfer notice listing its own carton licence plates, and the client ERP posts the stock straight to the new site instead of a transit location.
3. Monday 07:45: the new site checks the seal, which matches, but its WMS rejects the transfer notice because none of the 214 licence plates exist in its database; the trailer is parked in the yard pending relabelling.
4. Monday 11:00: the client ERP shows the 214 cartons as available at the new site, so order release allocates 96 customer orders against stock the new WMS cannot see; the orders sit unpicked.
5. Wednesday 15:30: customer service escalates 340 backorder lines; the transition lead traces TO-88412 to the yard, relabels the cartons and receives them by 19:00.

Under the controlled plan, licence plates are loaded into the new WMS before the trailer leaves, the client ERP holds the cartons in a transit location for TRL-5531, and order release cannot allocate transit stock. The trailer is receipted Monday morning and no customer order waits.

Transition reconciliation worked in dollars and rupees

The reconciliation should explain every unit between the frozen book balance and the stock received at the new site, then assign each variance to a party under the contract. The worked example uses one SKU family with illustrative figures.

Assumptions: 48,600 units on the client's books at the outgoing site at freeze; unit cost $14.20 in the US case and ₹1,150 in the Indian case; a contractual shrink allowance of 0.2% of units held, which the client absorbs; and transit damage claimable from the carrier subject to its liability terms.

The final transfer variance of 0.107% sits just above the 0.1% tolerance, so the close-out needs a documented cause rather than a silent write-off. Here the cause is clear: 45 cartons damaged on one trailer, with photos and a seal record supporting the carrier claim. In the Indian case the 97 units written off and the 45 damaged units also need input tax credit reversed under section 17(5)(h).

Go-live gates and the final switch-over checklist

Each phase of the transition should open only when its gate is passed and signed. The gates below turn the calendar into decisions, so a slipped integration test delays the inbound redirect instead of surfacing as backorders.

If you are planning a switch and want the transition plan, transfer messages and reconciliation reports set up before notice is served, you can send us your requirements. More warehouse and 3PL guides are in the logistics and supply chain section.