If you're looking to credit airline miles to your account, there are a few things you'll need to keep in mind. First, you'll need to determine which airline's miles you'd like to credit. Once you've done that, you'll need to find out if that airline has any partners with whom they share mileage programs. If so, you may be able to credit your miles from those flights as well.
Once you've determined which airline and/or partner airlines' miles you'd like to credit, the next step is to check what kinds of flights are eligible for crediting. Most often, only flights taken on the particular airline or its partners will qualify; however, some airlines also allow certain other types of flights (such as award travel or code-share flights) to be credited as well.
Finally, once you know which flights are eligible for crediting, the last step is simply providing your flight details (date, flight number, etc.) to the relevant customer service representative when prompted. With all this information in hand, crediting your hard-earned airline miles should be a breeze!