International Drivers Permit vs. Inter-Americ
The International Drivers Permit and the Inter-American Permit are quite similar in nature. Therefore, many people have questions on the differences between the two permits.
The International Driving Permit (IDP) is used as the official translation to the US driver license. Since more than 100 countries do not recognize the driver licenses from the US, the IDP shall be the alternative license for those countries to recognize. Please note that the permit could not replace the valid licenses in the US. On the other hand, the IDP shall only be used as the supplement. As long as the driver license is valid, the IDP shall be valid. However, the valid period for the IDP is only one year. Before your departure, you shall contact the American Automobile Association (AAA) to apply for the IDP.
The Organization of American States Convention on Regulation of Inter-American Automotive Traffic issues the Inter-American Driving Permit (IADP). With the permit, the drivers can drive vehicles in South and North American countries. However, the drivers need to have their valid Driver Permit from their home countries. At the same time, you can still contact the American Automobile Association (AAA) to apply for the IADP.
From the above discussion, you shall understand that the International Driving Permit and the Inter-American Permit are similar in nature. With your valid driving license in US, both permits allow you to drive outside the US. Both permits can also be issued by the American Automobile Association (AAA). However, they have minor differences. For the IDP, they in fact are the translation from the official US license. On the other hand, the IADP is not the translation, but you can only use the permit in the South and North American countries. Therefore, before departure, you are suggested to contact the American Automobile Association (AAA), and clarify it.