To mark an invoice as paid, click on the transaction and select More, then choose the Record Payment option, Samm.

Recording the payment manually will automatically mark the invoice as paid. However, keep in mind that swiping left on the transaction and selecting More will not show the Record Payment option. To access it, follow these steps:

1. On the Invoice page, click the entry you want to update.
2. Tap More in the bottom-left corner.
3. After that, choose Record Payment.

Refer to the screenshots below for a visual guide to the available options.

If the option to mark the invoice as paid is still not showing, I suggest refreshing the app's data to ensure all features for your invoice are loaded. Here's how:

For Android:

1. Navigate to the Home menu or tap the three dots in the bottom-right corner.
2. Select Settings and choose Refresh Data.
3. Tap Yes to confirm.

For iOS:

1. Go to your device Settings and select General.
2. Open iPhone Storage and tap the QuickBooks Online app.
3. Click Offload App to clear storage while keeping your documents and data intact.
   

If the issue persists, uninstall and reinstall the app to start on a clean slate. You can also record invoice payments by accessing your QuickBooks company using a mobile browser.

Please let us know if you have additional questions. We're here to assist.