If I have 3 rental properties, should I split common expenses (gas and office supplies) evenly between them or does it not make any difference?

[TurboTaxSusan]

Ultimately, all three of your T776 Rental Statements will get reduced down to just Lines 12599 and 12600 on your tax return. But you may find it more useful in the future to be able to see the amounts of the expenses for each rental, rather than have all expenses on only one of them.