When you detect that an incorrect agent is paid you have the option to (re) assign the Assignment Code to the correct agent. You can also transfer the account if the value you are using / importing for Assignment Code and Account is the same.
Important Note: If you find that after transferring an account it is reverting after calculation or after moving an Assignment Code is causing more items to be moved than desired it means your Import Matrix/Transfer has the Assignment Code and Account Number as two separate values. If it is an Intelisys transfer/matrix please set Assignment Code to Account Number and Account Number to Account Number, then delete the items and re-transfer/re-import them into your current run. The reason for this is if Assignment Code is a different value from the Account Number it will group all the Account Numbers under that Assignment Code and will force you to move all the Accounts at once. Intelisys uses their own Sales Agent ID as their Assignment Code so if you want better control over which accounts are assigned make the Assignment Code field from their transfers/matrices be Account Number.
An easy way to know which Assignment Code you need to assign is to have a second window open with the items, if you view an individual item you will find the Assignment Code in the Info area showing in the screenshot below.
Top menu >> Reps >> View the rep
Click Add an Assignment Code located in the Assignment Code box
Choose Existing Assignment Code
Select the supplier by clicking on the supplier name
Leave the radio button From assigned codes and find the Assignment Code in the dropdown or paste the code if you have copied it.
Finish when done.