To add the Paid Stamp you will have to customize your invoice form to include the stamp. Go to your top menu bar and choose Customize Forms > Invoices. Then select the customized form that you use and click Customize. At the top of the customization window click on Fields > Data-Every Page, check off the “PAID Stamp”, and click Add. Then you can move and resize the Paid Stamp for how you wish it to display on your invoice.

Check out our YouTube video on adding the Paid Stamp to your invoices: