What common mistakes are made when completing the Michigan Home Heating Credit Claim (MI-1040CR-7)?

Common mistakes made when completing the MI-1040CR-7 include:

Filing after the deadline of September 30th
Failure to report total household resources from all sources including gifts of cash/expenses paid on your behalf and Social Security benefits received on behalf of a dependent
Entering monthly amount of income (various types) instead of annual amount in total household resources
Incorrect or missing Social Security number(s) for eligible filers and/or dependents
Entering incorrect heat amount
Failure to mark box 10 if your heating costs are currently included in your rent
Entering figures on the wrong lines or not entering figures on required lines
Illegible writing
Using a name and address label with incorrect information
Computation errors (addition, subtraction, etc.)

What common mistakes are made when completing the Michigan Home Heating Credit Claim (MI-1040CR-7)?