The error is most likely being caused by trying to use the
Simplified Method for more than one home office.
According to IRS Publication 587, “If
you used more than one home in your business during the year (for example, you
moved during the year), you can elect to use the simplified method for only one
of the homes. You must figure the deduction for any other home using actual
expenses.”
You can correct the error by changing one of the home
offices to use the actual expense method for the calculation. If you rented one of your homes, it would
make things simpler to use the home office in the rented home as the one
claiming actual expenses.
