Hello there, ShopAdmin.
I can share a few information on how you can add your customer's contact information.
I presume you manually added a custom field where you can add the customer's phone number. While the option to select or automatically populate the customer's phone number from that field is unavailable, you'll want to manually enter the data.
If you want to update a customer's information, ensure that you do it on the customer's profile instead of on the invoice or sales receipt. If you do so, it will only apply to that transaction, and the customer's address is not updated on their profile.
QuickBooks will not retroact so if every time you update a customer's information, and you need to update existing transactions, you'll have to edit or toggle each transaction.
Feel free to use these link that will help you handle customer transactions and reports:
Keep me posted if there's anything else that you need help with. Have a good one!
