How do I import data to populate customer custom fields?

Hello, jeff-mountainvie. 

Thank you for choosing QuickBooks as your accounting software. 

I'm here to lend a hand and guide you on how to import your data to populate in custom fields in QuickBooks Online.  

First, we need to turn on the Custom fields option. It's super easy. Here's how:   

1. Click the Gear icon, then select Accounts and setting. 
2. Press Sales, under Sales form content. Then click the pencil icon and turn on the Custom Field. 
3. Tap Done once finished. 

After enabling this feature, you can use the sample format and start mapping your template fields. 

To learn more about custom field and the whole process, you can check out these articles: 

• Create and edit custom fields in QuickBooks Online Advanced. 
• How to add custom fields to invoices. 

Let me know if there's anything else you need. I'm always here to provide support and help. Have a great day, and stay safe!