You can remove the phone number of your customers from invoices by following the simple steps below.
Step 1: Open Simple Invoice from your Shopify store’s “Apps” section.
Step 2: Click on the “Templates” on the Simple Invoice dashboard.
Step 3: Click on the Options section, and unclick on the Show Shipping Phone, the Show Billing Phone, and the Show Customer Phone options under the Order Details.
Step 4: Click on the Save button.