Run the two warehouses in parallel for one to two weeks. Reconcile inventory at the old 3PL first, ship a first tranche to the new one, receive and count it, connect the store to the new location while the old one still ships, then cut over channel by channel: Shopify first, marketplaces after, FBA replenishment last. Give notice only after the new warehouse has received its first shipment. Never let both locations be "live" for the same order.
First, be sure the problem is the 3PL
Brands switch for four reasons that hold up: rising fees or surprise charges, chronic late shipments or errors, no support in your language or time zone, and the 3PL cannot do something you now need (FBA prep, kitting, B2B, a second channel). Brands also switch for reasons that do not hold up: one bad month at peak, a quote that looks cheaper but hides receiving and storage, or a problem that is really in the brand's own SKU data. Read what fulfillment costs and compare the same month line by line before deciding.
The transfer sequence
- Read the contract. Notice period, exit or "closing" fees, who pays for outbound labor and pallets, and how long you have to remove inventory after termination. Do not give notice yet.
- Request a full inventory count from the old 3PL, in writing. By SKU and lot, with units and cartons. Compare it with your system. Resolve every discrepancy now, while the goods are still under their control and their liability.
- Set up the new account and send the SKU map. Weights, dimensions, barcodes, carton counts, handling flags, packing instructions, kits. The new warehouse cannot receive well what it does not know about.
- Move a first tranche, not everything. Two to four weeks of stock for your fastest SKUs. The old warehouse keeps shipping from what remains. Marcana receives pallets at $25 each and boxes within your plan allowance, counts and photographs them, and confirms the receipt before you cut anything over.
- Connect the store to the new location and run test orders. One per channel, checked for the right packing slip, packaging and tracking.
- Cut over Shopify and DTC first. Switch the fulfillment location, watch a full day of orders, confirm tracking is posting back.
- Then marketplaces. Amazon FBM, Walmart, TikTok Shop: update the ship-from address and handling time, switch, watch.
- Move the balance. Once the new location is shipping every channel cleanly, transfer the remaining inventory, reconcile the final count against the old 3PL's report, and give notice.
- Close the old account. Final invoice, return of any custom packaging, confirmation that no inventory remains, and removal of the old location from every channel so a stray order cannot route there.
What happens to Amazon FBA during a switch
Inventory already inside Amazon's fulfillment centers is not affected by a 3PL change; it belongs to your seller account, not to the warehouse. What moves is your prep and replenishment flow: where reserve stock sits and who labels and forwards the next shipment. Time the switch so the next FBA replenishment ships from the new location after its first tranche is received and counted, and keep enough stock at Amazon to cover the transfer weeks. Amazon removal orders during the transfer should go to the new address.
What the switch costs
Illustration: 6 pallets, 300 orders a month, two-week overlap
| Old 3PL outbound labor and pallets | Per the old contract, commonly $25 to $60 per pallet |
|---|---|
| Freight between warehouses | Quoted by your carrier; the largest line if the move is cross-country |
| Overlap month at the old 3PL | Their plan and storage for the extra weeks |
| Marcana receiving, 6 pallets × $25 | $150 |
| Marcana Growth plan | $179 per month, starts when you sign |
| Inventory verification on arrival, optional | From $4 per box |
The overlap is the cost founders try to skip, and it is the cheapest insurance in the whole move. One month of two plans is less than one week of missed orders at peak.
Mistakes that cause stockouts
- Giving notice before the new warehouse has received anything. Service at the old 3PL drops the day you resign; make sure you already have a second location shipping.
- Moving everything at once. Two weeks in transit with no inventory anywhere live.
- Switching every channel on the same day. One integration problem becomes a full outage.
- Not reconciling before the move. Shortages discovered at the new warehouse become an argument between two 3PLs with you in the middle.
- Leaving the old location active in a channel. A single order routed to a closed warehouse is a refund and a bad review.
Questions founders ask
For a brand with clean SKU data, three to five weeks end to end: one week of setup and reconciliation, one to two weeks of first-tranche transfer and cutover, and one to two weeks to move the balance and close. Bigger catalogs and kits take longer to document than to move.
Not until the new warehouse has received and counted your first tranche. Read the contract for the notice period and plan the timeline around it, but keep the old account fully active until the new one is shipping.
Yes. The old 3PL ships pallets or cartons to your Marcana suite like any inbound; declare it in advance with the pallet count and packing list. Receiving is counted and photographed so the count you get is independent of the old 3PL's report.
Shopify connects to Marcana's ShipHero portal on the Growth and Scale plans; it is a new connection, not a rebuild, and orders start routing once the location is switched. Amazon FBM and other marketplaces are connected the same way, and FBA inventory is unaffected.
That is why the sequence starts with a written count from the old 3PL and ends with a counted, photographed receipt at the new one. Discrepancies between the two are raised with the old 3PL against their own report, with photos, within their claims window.