On February 29, 2012, we will be sunsetting the following versions and services:
  • AdWords API versions v13, v200909, v201003, v201008, v201101
  • AdWords API version v13 AccountService will only be available on a whitelist basis.
Calls made using these versions will return errors after February 29th. It is therefore critical that you migrate to AdWords API v201109 if you would like your applications to run without interruption.

We encourage you to use the following resources for a successful migration:
Posted by Katie Miller, AdWords API Team