Problem
After updating your company's phone number in Settings > Your Account > Company Profile, the old phone number is still displayed on printed invoices.
Solution
Go to Settings > Operations > Business Units.
Click the Edit button for the business unit you want to update.
Scroll down to the Invoice Header field.
Remove the old phone number and enter the correct one.
When finished, click Save.
Repeat steps 2-5 for each business unit that needs to be updated.