Indiana Code Title 3. Elections § 3-7-33-3.7

Sec. 3.7. (a) This section applies to a voter registration application submitted to the election division in person or by mail.

(b) An eligible applicant:

in person to the election division not later than 5 p.m. on the twenty-ninth day before an election shall be registered to vote in the election.

(c) An eligible applicant:

by mail to the election division shall be registered to vote in the election, if the application is postmarked not later than the twenty-ninth day before the election.  If a postmark on an application submitted by mail is missing or illegible, an eligible applicant shall be registered to vote in the election, if the application is received by the election division not later than the Monday following the close of the registration period.

(d) The election division shall promptly forward an application received under this section to the county voter registration office of the county where the applicant resides.  However, the election division shall not transmit to a county voter registration office an application that cannot be processed during the period when registration is closed under IC 3-7-13-10 until at least seven (7) days after the date of the close of registration.  The election division shall clearly identify the applications described by this subsection in the transmittal to the county voter registration office as “late registrations”.