What reference number would I use on bill payment?

CREATE ONLINE BILL PAY DEPOSIT NOTIFICATION

IBKR accepts online bill payment as a funding method, which is a check or electronic fund transfer that originates from an online payment service provided by your financial institution. IBKR does not charge a fee for funding an account using Online Bill Pay…

It is not possible to fund an IBKR account via an ecurrency wallet at this time.

For more information on how to fund your account, please see How do I transfer funds to IBKR?…

At this time we do not support recurring Online Bill Pay deposits. 

Additional Information…

IB HK does not support Online Bill pay. You may consider other transfer methods such as "wire" or "telegraphic transfers".

Additional Information…