On the quick books app,my outgoing invoices are saying " not sent" when they have actually been sent, WHY?

Hello there, deadlyseriouspes.

I'm here to share some information about the invoice status showing as Not sent in QuickBooks Online.

Before we start, could you please tell me what device you're using for your QuickBooks Online app?

If you're using an iOS device to access the mobile app, I recommend contacting our Support Team because we have an ongoing investigation regarding invoices that were sent but are now showing as not sent. This is also to confirm if you're one of the affected users and will be receiving important updates about the issue.

Otherwise, if you're using an android device, we perform some troubleshooting steps to fix it. We can delete that old data by emptying its cache and use QuickBooks with a clean slate.

Mobile App:

1. In your QuickBooks Online Mobile App, go to the Gear icon. 
2. Choose the Refresh Data menu. 
3. Click Yes.

Android Settings:

1. Go to Settings and select Apps.
2. Choose QuickBooks Online and click on Storage.
3. Select Clear Data.

I'm also adding this article that you can use as a future reference: Track the status of invoices in the QuickBooks Online mobile app.

Please let me know if you still have other concerns about invoices. I'll be around if you need help. Have a great day!