Do-Not-Call Improvement Act of 2007 - Prohibits having a specific expiration period for numbers in the do-not-call registry of the Telemarketing Sales Rule.
Requires the Federal Trade Commission (FTC) to reinstate the registration of any telephone number that was removed from the registry before enactment of this Act under an FTC rule or practice requiring the removal of a telephone number from the registry five years after its registration.
Authorizes the FTC to check telephone numbers listed on the do-not-call registry against national databases periodically and purge numbers that have been disconnected and reassigned.
Requires the FTC to report to Congress on FTC efforts taken after enactment of this Act to improve the accuracy of the registry.