When I am trying to change the payment method for the QuickBooks subscription, I am not getting an active "Save" button.

Welcome to Community, CIPL.

Let's make sure you're able to successfully update your payment method for your QuickBooks Online (QBO) subscription.

This behavior where you're not getting an active Save button when changing your payment method can be fixed by performing some basic browser troubleshooting.

Here are a few steps to narrow down the cause of this issue:

• Login to your QBO account using an incognito or private browser. Since this doesn't store data in the cache, it the best place to isolate browser issues. Kindly use either of the following shortcut keys:
   
  • Google Chrome, press CTRL  + Shift + N
  • Mozilla Firefox: press CTRL  + Shift + P
  • Internet Explorer: press CTRL  + Shift + P
  • Safari: press Command + Shift + N 

Then try changing the payment method of your QuickBooks Online subscription again. You can have the steps below as your guide:

1. Go to the Gear Icon.
2. Choose Account and Settings.
3. Select Billing & Subscription.
4. Enter the credit card information. 
5. Make sure to verify the billing address in QuickBooks Online is the same billing address on the credit card statement.
6. Click Save Changes.

• If you’re able to edit your payment method successfully, you may want to clear the browsing history of your regular web browser. This will remove previously-stored browsing data that might have caused the issue. 
• Otherwise, you can try using other supported browsers to be thorough.

Feel free to visit this link where you can gain more tips and articles for future use: Welcome India customers to Global Community.

For additional queries, leave a comment below. I'll get back to you. Have a good one.