Thanks for dropping by here in the Community, @lewis-hayward-ou. I'll help you sort this out so you can proceed to apply the customisation to your invoice.
When a user encounters problems with QBO that appear to be browser-related, we recommend that they clean their cache. Temporary internet files increase loading performance, but too much can build up and cause operations to slow down. To start, here's how:
1. Restart your browser.
2. Log in to your account and try to customise your invoice in an incognito or private browser. You can use these keyboard shortcuts to launch a new private window:
- Google Chrome: press Ctrl + Shift + N
- Mozilla Firefox: press Ctrl + Shift + P
- Safari: press Command + Shift + N
3. If it works on the private browser, you can go back to the regular browser and clear your browser's cache. From there, try to customise your invoice.
Feel free to visit this article for the steps to add your bank details into your invoice: Adding bank details to your invoices.
Additionally, I'll leave these articles for future reference:
Feel free to get back to me in case you have any additional QuickBooks concern. Rest assured, I'll always be here to help you. Keep safe and enjoy the rest of the week!