The billing terms on your account can be updated in the Web Portal > Settings Cog > Accounts > Invoices > Scroll down to Default Invoice Payment Terms > make changes > Save at the bottom of the page.
On the App > Login > Settings cog in bottom right > Invoices >Scroll down to Default Payment Terms > make changes > Save.
You can also change billing terms for individual customers in the CRM > Contacts > Edit Pen for contact > Billing Terms.
