Within QuickBooks Online, you have the ability to add custom fields to your Customers and Sales Forms, and Purchase Orders.
Unfortunately, QuickBooks does not expose all of their custom fields for Method:CRM to sync with. At the moment, Method:CRM ONLY syncs with the first three custom fields of your Sales Forms and first three custom fields of your Purchase Orders. Method:CRM does not sync with the Customers custom fields.
In Method:CRM, the custom fields from the Sales Forms, sync to the estimate, invoice, and sales receipt tables.
Furthermore, even though the first three custom fields will sync over to Method:CRM where you can customize screens to access the fields, there are still limitations to the custom fields once they have synced over. They cannot be renamed after they sync to Method:CRM.
In the below example, the QuickBooks invoice template has been customized to include three custom text fields: Region, Rink Type, and Season.
When you first create these three custom fields, they will sync over to Method:CRM's Invoice table with the same names. In the case of an illegal character, such as a space, this will be removed.
The below screenshot highlights in green the three custom fields we created for the Invoice table as seen in Method:CRM:
Once created, the names of the custom fields cannot be edited! Doing so will generate a sync conflict, so do not rename or delete a custom field in QuickBooks Online after you have created it.