Originally Posted by miro
I think it's 30 days fo DL and 90 days for partner activity (at least for missing mileage claims).
Yes, 30 days for DL, CO, and NW.
Originally Posted by delta.com
If mileage credit for a qualifying Delta/Delta Connection® flight or qualifying partner activity is not recorded on your statement within 90 days (30 days for Delta/Delta Connection, Continental Airlines or Northwest Airlines), please follow these procedures: