To make it easier for Windows Azure customers to keep track of their compute hours usage, "Microsoft's now sending customers emails notifications when their compute hour usage exceeds 75%, 100% and 125% of the number of compute hours included in their plan. Customers on standard consumption offer will receive, for the first 13 weeks of their subscription, email alerts every week with their compute hour usage for the previous week. After 13th week, customers will receive email alerts when their compute hour usage exceeds 75%, 100% and 125% of their monthly usage based on a three-month rolling average. Customers can also view their current usage and unbilled balance at any time on Microsoft Online Services Customer Portal. The e-mail address used for the communication is the same address used when creating the billing account," explains Microsoft.
More Info: MOS Customer Portal