In the past I applied for an EIN but forgot the number. How to do I retrieve this number?

Once you have applied and received a number, you cannot reapply to get a new number. If you forgot your number simply call [phone] and select EIN from the list of options. Once connected with an IRS employee, tell the assistor you received an EIN from the internet, but can't remember it. The IRS employee will ask the necessary disclosure and security questions prior to providing the number.