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For a fast and secure transaction, your customer can electronically sign their invoices and estimates on your phone or tablet using the QuickBooks Online mobile app.
Tap Save if you're using an IOS device. If you're using an Android device, select Done.
Choose Get Signature, then have your customer sign the invoice with their finger.
Tap Done to complete the process.
This feature isn't yet available when using the web version in sending the invoices. For now, I recommend visiting our QuickBooks App Center to find a third-party application that allows approval of invoices via electronic signature.
You can also follow these steps in searching the app inside the program: