Hello, mvit. 

It's good to see you here in the Community. Updating the GST rate needs to be done manually, as well as your recurring transaction in QuickBooks. That said, you'll need to create a new tax rate in QuickBooks. Before we proceed, please take note some reminders below: 

• Existing transactions that used the earlier rate remain unchanged unless you edit the transaction and specifically select a different GST rate.
• For recurring templates that use the changed component, new transactions created with the template use the new rate. Existing transactions created with the template and the earlier rate remain unchanged.
• The new rate will be available for new transactions entered after the Effective date. 
• If you create a new transaction dated before the set Effective date, the transaction uses the old rate. 
• If you create a new transaction but use dates in the past, the transaction uses the new rate. 

Now let's go ahead and create a new GST rate in QuickBooks. 

1. Go to Taxes.
2. Select Add tax. 
3. Choose What type of tax do you want to add?
4.  Enter all the information needed. 
5. Press Save once done.  

Once finished, you can modify the recurring transaction manually. Please visit this article for more details about recurring transactions: Edit a recurring template.  

When you run reports the data still show for both rates (before and after) if there are transactions for both the rates in a particular period. 

That's it. Please don't hesitate to reach out here in the Community. If you have clarification about tax rate in QuickBooks. Take care!