Product: Acumatica
In order for Transaction Manager and Acumatica to link your Trading Partner (Transaction Manager) with your Customer/Vendor Profile (Acumatica) so they know which EDI connection pairs with what customer records within your system you'll need to configure the Partner Setup within Transaction Manager.
Acumatica Profiles
Transaction Manager syncs to your Acumatica system by linking your Customer or Vendor ID into Transaction Manager's Partner Setup
Customers (Receivables)
If you would like to receive Purchase Orders (850) from your Trading Partner you would set this partner up as a Customer within Acumatica which would show up under the Receivables module
Navigate: Receivables → (Profiles) → Customers
Vendors (Payable)
If you're planning to send Purchase Orders (850) to your Trading Partner, then you'd want to setup your partner as a Vendor under the Payables module
Navigate: Payables → (Profiles) → Vendors
Syncing Trading Partners
You can use the built in Sync option within Transaction Manager to automatically pull the Customer ID exactly as needed.
Navigate: Trading Partners → (Partner) → Translations → Partner List
Select: Sync
Select: Magnifying Glass to Perform Search
Select: Sync Selected Business System Partners
Manually Adding a Partner
If you would like to manually add a Customer ID into Transaction Manager you can do so by grabbing the Customer ID from Acumatica and placing it within the Partner Setup list.
Navigate: Trading Partners → (Partner) → Translations → Partner List
Select: Add Partner
Enter: Customer/Vendor ID from Acumatica