Hi, I’m in the UK and the billing has increased by 100% from last month to this month of from £12 per month to £24 per month?

Hello @adrianliddell-bt,

A change with your billing and subscription takes place if you bought the product during its promotional period. In your case, I'm assuming the period where you can use QuickBooks with a discounted subscription has ended.

With this, I'd recommend contacting our Customer Care Support. With their tools, one of our specialists can pull up your account on file and discuss how your account subscription is billed. To do so:

1. Go to Help.
2. Select Contact Us.
3. Enter Billing and Subscription Increase in the What can we help you with? field.
4. Click Continue.
5. Choose a channel where you wish to connect to our dedicated support.

Additionally, I've also included this reference for a compilation of articles you can use while working with us: Account Management for QuickBooks Online.

If you have any other questions, please let me know in the comments below. I'll be here to lend a hand.

@adrianliddell-bt 

Did you open the account a few months ago? Your discounted rate might be ended. You may open a new blank QBO account and migrate data from the old account if required. They offer a huge discount currently.

https://quickbooks.grsm.io/UK