Upon saving the Purchase Order, the Vendor field becomes grayed out.

  1. Delete the incorrect Purchase Order.  If the record is posted, reversing entries will be created.
     
  2. Recreate the record for the appropriate vendor.**
**Note: If you'd like to use the same PO number:
  1. In Configuration
  2. Click Business Rules
  3. Highlight Purchase Order
  4. Unmark checkbox to Automatically generate Purchase Order IDs
  5. Recreate Purchase order
  6. Follow steps 1-3 again
  7. Mark the checkbox to Automatically generate Purchase Order IDs