How to Transfer Miles Between Programs
Several frequent flyer programs offer as an award option the ability to "transfer" miles/points from their program to another program. These transfers aren't generally any different from any other award option in that, what you are essentially doing is redeeming some of your miles/points for (usually fewer) miles/points in another program.
While transferring miles can be beneficial in some circumstances, it will generally result in an overall loss of value and so should be undertaken with care.
How to Complete a Mileage Transfer
The first step to any conversion process is to contact the program from which you want to transfer miles/points. For example, if you wanted to transfer points from the Hilton HHonors program into an American AAdvantage account, you should call Hilton HHonors to initiate the transfer process. The miles can often take up to eight weeks to appear in the destination account, so if you need the miles to book an award be sure to initiate the transfer as soon as possible.
If you are following a multi-step conversion path (e.g., Hilton HHonors -> American AAdvantage -> InterContinental Priority Club Rewards), you should treat each step as a unique conversion. For example, once the points have been transferred from Hilton HHonors into AAdvantage miles, you would contact the American AAdvantage program to initiate the transfer to InterContinental Priority Club Rewards.
In other words, when you contact the first program in the path (from which you are transferring out of), you need only inform them of the first step of the conversion path. Following the conversion path mentioned above, for example, you would start by contacting Hilton HHonors and informing them you would like to transfer points into your American AAdvantage account. Then, once that step is completed, you would contact American AAdvantage and inform them you would like miles transferred into your InterContinental Priority Club Rewards account. If you were to inform Hilton HHonors you wanted to transfer points into InterContinental Priority Club Rewards, you would most likely be told this is not possible as there is no direct transfer option between the two programs.
WebFlyer.com offers a Mileage Converter tool that allows you to input origination and destination programs and find all possible conversion paths between the two programs.