Company ‘trusts’ users to voluntarily stay within bounds
On Thursday, Microsoft took the unprecedented step of launching a dedicated version of its Office productivity suite for the Apple iPad, giving all iPad users the ability to view Office documents on the go for free, and those willing to pay $100 per year for an Office 365 subscription the power to edit and create them. There’s a slight problem, though.
"Similar to our commercial use rights, we do not strictly enforce the limit on tablet installations, but trust that our users respect and understand the device limits outlined in the EULA [end user rights agreement]," Microsoft told CNET when asked about the loophole.
So to sum it up, while it is technically possible for you to use a single subscription with more than five iPads, it is something Microsoft would like you to avoid in keeping with the EULA.