Why can't I see the custom form styles page? When I try to access this page I get an error saying "We're sorry, we cant find the page you requested".

It's good to know that you did some troubleshooting to fix the error, Kerry, and I appreciate you for that. 

Upon checking here in the system, we have an ongoing investigation into this feature being inaccessible in QuickBooks. It means that other users are experiencing the same concern as well. Please be assured that our product engineering team is working diligently to resolve this issue. Hopefully, you can access the feature as soon as possible.

To ensure that you are included in the list of affected users, I recommend contacting our QuickBooks Support team. Once added, you will receive email updates regarding the status of the investigation.

They can be reached while using QuickBooks. Here's how:
 

1. Go to the Help icon in the top right-hand corner.
2. Select Search, then press the Contact Us button.
3. Enter your question in the box and hit Continue.
4. Choose the best way you'll want to reach out to us.
    

Be sure to review their support hours so you'll know when agents are available. In the event you're unable to reach out to Intuit through your books, you can get in touch through our website.

Additionally, I've attached the article that can guide you with the customization as soon as you can access Custom Form Styles in QuickBooks: Customize invoices, estimates, and sales receipts in QuickBooks Online.

Drop me a comment by hitting the Reply button if you need more assistance with the missing features in QuickBooks. The Community and I will be willing to help you out.

Hi Nicole, 

Thank you for your reply. I am still not able to edit or customize invoices. Could you please escalate this issue with your software team? I have been in touch with customer service via chat and phone, and no one seems able to help. Creating invoices is an essential function, and if this is a known issue, it should be resolved quickly. Thank you for your help!

I appreciate the follow-up response, Kerry.

As per checking, the abovementioned investigation is still ongoing. Rest assured that our software engineers are diligently implementing measures to provide a fix as quickly as possible so you can get back to customizing your sales forms seamlessly in QuickBooks Online (QBO). If you are already on the list of affected users, you will receive email notifications once the issue has been resolved.

Furthermore, when a customer makes a payment, you need to record it in QBO to mark it as paid. If not, the invoice will remain open and unpaid in your reports. 

I appreciate your utmost patience and understanding as we're working on a resolution. If you have additional questions about customizing sales forms, please don't hesitate to swing by the Community. I'll respond promptly to continue assisting you. Keep safe.