Microsoft have announced that starting from the 1st of January 2017, prices are set to increase because of the decreasing value of the pound. All quotes taken directly from Microsoft's Technet Blog Post
Microsoft are moving its prices towards Euro levels as the currencies approach parity. “From January, British pound prices for on-premises enterprise software will increase by 13% to realign close to euro levels. Most enterprise cloud prices in British pounds will increase by 22% to realign close to euro levels. Even after this adjustment, customers across the region buying in British pound will still find our cloud offerings highly competitive"
For all contracts / agreements with Microsoft, the prices will not increase until the agreement ends or is renewed, which means that now would be the best time to purchase a new Microsoft product / licence. "For business customers, these changes will not affect existing orders under annuity volume licensing agreements for products that are subject to price protection. For example, customers with Enterprise Agreements have price protection on previously ordered enterprise software and cloud services, and will not experience a price change during the term of their agreement. Similarly, business customers with cloud commitment subscriptions such as Office 365 also receive price protection during their subscription term, which is normally twelve months from the start of paid subscription."
All customers who buy their Microsoft products via a partner will not automatically change, and it will be up to the partner to update prices themselves. “For indirect sales where Microsoft products are sold through resellers, final prices and currency of sale will continue to be determined by them.”
Microsoft said what it called "harmonisation adjustments" were similar to those it made to pricing in Norway and Switzerland, after movements in the krone and Swiss franc earlier this year. "We periodically assess the impact of local pricing of our products and services to ensure there is reasonable alignment across the region and this change is an outcome of this assessment".