PS Plus users in the UK have received an email saying that prices for the service, which is required to play online, will be increasing at the end of the August.

Prices for an annual subscription will be increasing from £39.99 to £49.99. For a quarterly subscription the cost will rise by £5 to £19.99, and on a monthly basis the price will increase by £1 to £6.99.

For those keeping track that's a 20% rise for those paying annually, and a 33% rise for those paying quarterly.

Prices are also increasing in Australia by AU$10 annually, AU$6 quarterly and AU$1 monthly. European prices, as well as prices in South Africa, are also set to increase.

And the reason?

The email offers little in the way of explanation for the change, instead concentrating on outlining the mechanics of how the price increase will be handled.

From the email, "We will alter the price of a PlayStation®Plus membership at 00:01 BST on 31 August 2017. As you are an existing member, this means that all recurring subscription fees payable by you on or after 31 August 2017 will be charged at the new price."

"Up until 31 August 2017, you may purchase a PlayStation®Plus subscription at the current price, which will then be added (or “stacked on”) to your current membership period."

When contacted, a representative from Sony said, "We are changing the pricing to reflect various market conditions while enabling us to continue providing exceptional value to our members."

"Members will continue to enjoy the benefits and features such as online multiplayer, two PS4 games every month, new PlayLink social party game That’s You! as a bonus game until 25th October, exclusive discounts, and 10GB online storage for game saves."

The news follows a similar move in the US last year, where prices for the service increased to $59.99 on an annual basis.

The last price increase to be seen in the UK didn't result in a rise in the annual subscription, but did see the one-month option will rise from £5.49 to £5.99, while the three-month package jumped from £11.99 to £14.99.

Given these prior price increases, it might be the case that Sony is attempting to balance its prices worldwide. Alternatively this price increase might be due to the value of the pound, which has fallen sharply since the result of 2016's Brexit referendum was announced.

However, with no details given about new features coming to the service, users are unlikely to be happy about having to pay more for exactly the same functionality as they had before.

If you're looking to avoid paying more then it's possible to 'stack' subscriptions, meaning you can pay for additional years of membership now at current prices.