How can I change the format of my customer statements? The address doesn't fit in the window of my envelopes.

For some reason QuickBooks doesn't allow customization of their statements beyond your default customer information and logo in your accounts and settings. 

If you have a lot, I recommend switching to a regular envelope and exporting your open invoice customer list and putting them on labels to mail.  

Welcome to the Community space, CSoren. Let me clarify things by providing additional insights about this capability within the QuickBooks Online (QBO) program.

At this time, being able to modify the template on customers' statements isn't available in QBO. The only available customization with statements has been laid out in this article: Create and send customer statements in QuickBooks Online.

For now, I encourage you to submit feature requests to our product development team. Rest assured that they will review it and may consider this option for future updates, depending on the number of users' requests. Here's how you can submit feedback:

1. Go to the Gear icon at the top.
2. Select Feedback.
3. Enter your comments or product suggestions.
4. Then select Next to submit feedback.

Moreover, you can check out this article to review the recorded transactions and their statuses in the Sales menu: View sales transactions in QuickBooks Online.

I'm always around and ready if you need further assistance or have additional questions about customer statements in QBO. Just let me know by replying below.