Open your Internet browser and go to http://delta.com/mergeaccounts.
Click the blue "Merge Accounts Now" button.
Enter your Primary SkyMiles Number and PIN. This is the number that you want to use for your permanent SkyMiles account. Typically, this will be your original SkyMiles account number.
Enter your Secondary SkyMiles Number and PIN. This is the 10-digit SkyMiles number that you received from Delta in place of your old WorldPerks account number.
For your PIN, enter the PIN that you used to access your WorldPerks account. When creating the new SkyMiles account number, Delta assigned your old WorldPerks PIN number to the new account.
Click the blue "Validate" button.
Review the information you entered. If the data is correct, click the blue "Submit Merge Request" button. You'll receive an email from Delta in a week confirming your request and detailing your new status and account balance in the Delta SkyMiles program.Delta and Northwest airlines completed their merger in January 2010 resulting in one airline, Delta Airlines. At this time, Delta enrolled all the Northwest WorldPerks frequent flier accounts into the Delta SkyMiles frequent flier program. If you had a WorldPerks account at the time of the merger, Delta automatically transferred all of your miles and frequent flier status to a new SkyMiles account. If you also had an existing SkyMiles account, you will need to merge the new SkyMiles account with Northwest miles into your existing Delta SkyMiles account.