Amazon Will Deactivate the Legacy 'Amazon MCF: US Fulfillment' Shopify App on September 30, 2026 — Merchants Must Migrate to the New MCF and Buy with Prime App
Amazon is retiring the legacy Amazon MCF: US Fulfillment app for Shopify and deactivating it on September 30, 2026. Merchants using it to fulfill Shopify orders from FBA inventory must install and configure the newer Multichannel Fulfillment (MCF) and Buy with Prime app before that date or lose the Shopify-to-MCF connection. Amazon describes the new app as simplifying operations and expanding capabilities, adding Buy with Prime support and improved SKU mapping. The migration is not automatic — SKU mappings and order routing settings have to be re-established in the new app.
Real-World Impact
As of July 29, 2026 there are 63 days until the September 30 deactivation. Because auto-mapping only applies where the Shopify SKU string exactly matches the Amazon SKU, any catalog with mismatched naming has to be remapped by CSV import — a 500-SKU catalog with inconsistent naming is a bulk data task, not a one-click switch.
Key Points
- The legacy 'Amazon MCF: US Fulfillment' Shopify app will be deactivated on September 30, 2026
- Merchants must install and set up the new Multichannel Fulfillment (MCF) and Buy with Prime app for Shopify to keep fulfilling Shopify orders from FBA inventory
- Amazon positions the new app as adding Buy with Prime support and improved SKU mapping over the legacy app
- SKU mappings do not carry over automatically — Amazon documents a CSV export/import method to move mappings from the old app, and auto-mapping only works where the Shopify SKU name matches the Amazon SKU
- Amazon's documented migration sequence is: install and connect the new app, migrate SKU mappings, review Shopify order routing so 'Amazon Fulfillment' is ranked appropriately, test with sample orders, then uninstall the old app
- The new app supports partial order fulfillment and bundles, syncs inventory from Amazon to Shopify, and supports unbranded packaging with optional AMZL blocking
- Per Amazon's documentation, the app accommodates orders up to 250 units and 100 unique SKUs
What You Should Do Now
- 1Check which Amazon fulfillment app is installed in your Shopify admin — if it is 'Amazon MCF: US Fulfillment', you are on the app being deactivated
- 2Install and connect the new Multichannel Fulfillment (MCF) and Buy with Prime app and link your Amazon seller account
- 3Export your existing SKU mappings from the old app and import them into the new one via CSV rather than remapping by hand; verify that any SKUs whose Shopify and Amazon names differ actually mapped
- 4Review Shopify order routing rules (or Shopify Flow) so 'Amazon Fulfillment' is ranked where you want it, and confirm which orders should route to MCF
- 5Run sample orders through the new app to verify SKU mapping and shipping speeds before uninstalling the legacy app — do not wait until late September to test