Give both teams clear responsibilities
Identify who coordinates the stock release, carrier pickup, destination receipt, and order cutover. Share contact details and a short escalation path. Make sure someone is responsible for telling you when a milestone slips.
Start with a manageable handoff
Discuss whether a staged transfer is practical for your assortment. Review the first receipts and shipments together before treating the move as complete. Keep customer support informed about any temporary delivery changes.
Write a controlled handover plan
List the stock count, shipment preparation, receiving confirmation, system tests, and order-routing changes needed for the move. Give each step an owner and an acceptance condition. Identify the decisions that depend on the outgoing provider, the incoming provider, and your own team. Keep the target date separate from the date everyone has confirmed. Review your actual commitments with the appropriate advisers before relying on a transfer assumption.
Agree on how the teams will work
Use the brief to start a conversation with the people responsible for the account. Discuss where questions go, who owns a difficult answer, and how updates reach your team. Write down the arrangement in language both sides understand. The goal is a working agreement that still makes sense on a busy day, when the usual contact is unavailable or an order needs attention.
Use this question in your next meeting:
What must be confirmed before the next handoff can safely happen?
Go deeper: Switching 3PLs: the conversations to have first. The companion article includes an editable worksheet and links to provider profiles.
Further reading
Shopify: inventory states. Reference for the distinction between available, committed, and other inventory states.