Mismatched Returns

What is your best practice for handling cases returned with the wrong cartridges? Do you send it back to the patron? Do you notify the patron? How do you track this in KLAS.

We call all patrons to let them know what the issue is. We do not clear the item from the record. Usually, the items go on a shelf in DB order for ease of matching up the other halves. We also put a note in the patron's comments.

Sorry this is a little long.
In South Carolina, we return all mismatched or missing cartridges and containers to patrons with this note inside (attached). It is printed on bright yellow paper.
We go on the assumption that the matching cartridges and containers are at the patron's home.
A note is made on a spreadsheet of the patron's name and ID; book numbers of the mismatched cartridge or container; and the date received and sent back. Only one staff member actually handles the issue.
If the patron calls asking about the note or why the container was returned to them we explain what has happened and that our policy is to send them back to the patron to be matched up.
If the patron claims they were both sent back already or that they cannot match them up, we'll usually mark both NAC/LUN in the catalog and notify the staff member to be on the lookout for those two.
If they are sent back a second time still mismatched, a second note is made on the spreadsheet, and the cartridge and container go to a set aside area (separately).
Every week the assigned staff member checks to see if a match can be made from the mismatched ones. If so then they are checked in. Otherwise they stay on the patron's record. They may be marked lost by a Readers Advisor at some point in the future if a significant amount of time has passed.

We are copy specific, and we do clear the book off the patron record when one of the parts is returned. All of our books are checked in before they go to be inspected. That means they all get cleared off the patron record unless there is a GLARING problem. It didn't seem fair that patrons who return the empty box got it cleared off their record, but patrons who actually returned the cartridge did not--so we clear the book off in both circumstances.
Once we find the problem in Book Inspection, the mismatched parts go in a bin and one staff member handles them. Boxes that were empty when returned, or which had the wrong book inside, get changed to NAC/Empty in KLAS. Most importantly--the loose cartridges get changed to NAC/NoBox. These two circulation statuses cannot be changed directly to AVL, so even if the problem isn't noticed the first time it is scanned, they can't accidentally get assigned to a new patron. Once caught and matched up, the staff person who handles these scans them to NAC/InProcess, then AVL and reshelves them.
We tried calling patrons in the beginning, which was too labor-intensive. The Post Office chastised us for sending empty boxes back, so now we just gather the spare parts and wait for their match to be returned. When patrons inquire about spare parts, we tell them to mail it back, whatever it is. The cartridges seem to do fine in a standard paper envelope.

We did a seminar on this at the 2015 conference, and you can get the details from the Power Points linked under "Getting Back on Track: Processing Overdue & Mismatched Books." Or call or email me if you have any questions. Amy