I have only one as well.  In previous years, I "override" the dates at the top of the form.  This year since it has to be paper filed and that option was not available, I printed and wrote in red sharpie "fiscal year taxpayer and the dates".  Unfortunately they receive notice every year on their payments and must call the IRS every year to "remind" them they are fiscal year taxpayers so I also recommend getting a POA in conjunction with filing as you will most likely need it and possibly adjust your fees accordingly.