Warm welcome, MK12341. I'm here to ensure you can add your customer's VAT ID, company registration number, or other identification.

If you want to add an option wherein your customer can enter their VAT ID, company registration number, or other identification, please know this is currently unavailable. 

On the other hand, if you wish to add these details to distinguish your customer's information, you can include them in their profile notes.

Here's how: 

1. Hover to Sales, then click Customers
2. Double-click your preferred customer and tap Edit.
3. Enter the details in the Notes and attachments section, then hit Save.

I've attached a screenshot for visual reference.

For future reference, you can send customer statements in QuickBooks Online. This feature lets them view their invoices, payments, credits, and balance summaries in one place.

Whenever you need further assistance managing your customer's details, I'm here to back you up. Kindly utilize the reply button below to enter any queries you may have.