Microsoft's August price list has revealed increases of up to 15 per cent for Office 365 enterprise customers.
Those without a software assurance plan will be hit with the largest hikes, whereas those who do will have their prices frozen until the end of their contract.
It's not all bad news though. Existing customers will not experience any price increases when renewing their contracts and anyone who bought Office 365 from Microsoft or through its open licensing programme won't be affected.
"The vast majority of our customers will not see an increase in the cost of Office 365," said a Microsoft spokesperson. "All existing Office 365 EA customers are guaranteed prices will not change for the duration of their agreement.
"New Office 365 EA customers who don't have a previous investment in our products will see an increase to align our pricing to our other channels. We are always evaluating our pricing to maximize the value to our customers as we continue to add more features and benefits to Office 365. "
In an effort to counter this price increase, greater discounts will be offered for Office 365 E1, E3 and E4 subscriptions, which will be priced at $8 (£4.66), $20 (£11.66) and $22 (£12.83), respectively.
Office 365 is currently enjoying successful adoption rates across the boards and reportedly generates $2.5 billion (£1.46 billion) in annual revenue.