I am using QBO from UAE and trying to connect my Emirates NBD account to QBO. It asks for a Subscriber ID. What does that mean?

Welcome to the Community. I'd be glad to provide you with the information you need in your QuickBooks Online account, michelli-kloudac.
 

A company or subscriber ID is a unique identification number that's associated to a QuickBooks Online account.

We’ll have to go to the Billing & Subscription area of your account to get the company number. I’ll help and guide you on how to get there.

1. Click the Gear icon.
2. Choose Account & Settings.
3. Select Billing & Subscription on the left. The Company ID will be displayed at the top of the page in green.

You can locate information about this at the following link: How do I find my Company ID?.

Also, this article contains topics that will guide you on how to handle your subscription, privacy, security, etc: Account management.

Let me know if you have other questions about handling your account so I can help you from there. Take care!