TROUBLESHOOTING: Getting error from 3PL when on transfer order with multiple lines using the same SKU

Q: I have transfer orders from 3PL with multiple lines that use the same SKU, but when I run my flow, I get an error: “Failed to create, update/transform record because multiple lines found with keys itemkey=XXXX”

A: Multiple key errors is a common error when trying to fulfill an order by item name where there are duplicate items on the order.  The solution is to ensure that no duplicates exist on the order, or use another unique line identifier to fulfill, such as Line ID.  However, using Line ID will require cooperation with the 3PL, as this information will need to be sent when the original order is sent, then received back on fulfillment.

This could be caused in a few different ways:

• This error is caused by the field you are using to fulfill line items.  If you are using Item Name / Item ID to match on items to fulfill, this error will occur if there are multiple items with the same Item Name / ID.  To resolve this, you need a field to UNIQUELY identify each line (such as NetSuite Line ID), but this will require some effort in working with the 3PL to send this Line ID information to them when the order is originally sent, and then have them send it back.
• If you are using Item Name to fulfill line items, but are getting an error with your sublist when you try to map the line ID as a unique field, make sure that you have checked the checkbox Use as key field to find existing lines for your Line ID mapping. Also, verify the line ID against the record's internal line ID to ensure that they match. You can check this by manually fulfilling the record in the NetSuite UI, then adding "&xml=t" at the end of the URL to view the record as XML.  From there, you can search for the tag <line>, then check the line ID against the values that you're trying to map.