You can use the Other field or Notes section on the Customer information page to add more details.
If you want to add these details to your sales transactions, you can add this field and manually enter the information or copy and paste it from your notes. Let me show you how to add custom fields on invoices:
Go to the Gear icon and select Custom form styles.
If you have an existing invoice template, you can click Edit.
Select the Content tab. Scroll down to click the + Custom field option.
Check a box and enter a name for that field.
For more details on how to handle customer transactions and details, you click these links: