My father owns his own business and asked me to print a few checks on the smaller (personal) size check paper? I did not know this was possible, but he assured me that it was. I am confused about how to print MICR line. Do I print it with the check number first (it's a business account) or do I print it at the end (since it's going to be on the smaller check paper)?
That said, more to the question asked - you can definitely use the smaller "personal"-sized checks for a business account. The larger checks formatted to the "letter" page size: if you cut it into three equal pieces with a tiny bit left for the binder holes - you'll get exactly three check-sized pieces. This is convenient for those printing checks, keeping carbon-copy records etc.
Regarding the MICR line: I just checked my business check book, which is of a smaller "personal" size (that I got for free from the bank) - the check number is at the end.