If you have not used your Binance account for long you may forget your Binance ID. Do not be but it got to Binance username recovery page. Choose as an alternate e-mail address on mobile number which you provided by creating your Binance account. Enter the CAPTCHA code and click, submit. Binance will then send you a list of e-mail IDs associated with the phone number or alternate e-mail address that you have provided. In case you choose a phone number, you will receive the verification code. You have to enter this verification code and Binance display the list of user IDs associated. In all probability you will be able to recover your forgotten Binance ID. Call binance support number and understand the process better.

Resource link: https://speakjunction.com/binance-phone-number/