If I stupidly set up a sole trader subscription last year and should have set up a simple start subscription how do I change this?

You can upgrade your existing subscription within QuickBooks Online to automatically carry over your data and keep managing your business seamlessly.

To start, here's how:
 

1. Sign in to your QuickBooks account.
2. Go to Gear icon, and then Account and settings.
3. Select Billing & subscription.
4. Select Upgrade your plan and follow the prompts.

For more details, please refer to this article: Switch from QuickBooks Sole Trader to QuickBooks Online or Sole Trader Plus.

Feel free to click the Reply button if you have more questions about the program.