Once an EIN has been assigned to a business entity, it becomes the permanent Federal taxpayer identification number for that entity. Regardless of whether the EIN is ever used to file Federal tax returns, the EIN is never reused or reassigned to another business entity.
The IRS cannot cancel your EIN. However, if you receive an EIN but later determine you do not need the number (the new business never started up, for example), the IRS can close your business account. The FEIN will still belong to the business entity and can be used at a later date, should the need arise.
