You can apply online to obtain an EIN immediately as long as the IRS can verify your Social Security number. Other methods, including fax and mail, will take days or weeks to process. Foreign owners without a Social Security number must apply via fax or mail.

An EIN (aka Federal Tax ID) is like a Social Security number for your business entity that the IRS uses to identify you for tax purposes. You will need your EIN for many business-related purposes, including paying your federal taxes.

Without an EIN, your business will be severely restricted. If you want to have employees or plan to hire employees, you need an EIN. If you’re interested in running a corporation or partnership or filing Employment, Excise, or ATF returns, you’ll need an EIN.

EINs do not expire. Once an EIN has been issued to your business, it will not be issued again. If you have an EIN but lost, misplaced, or cannot remember it, you can contact the IRS to search their database for it.

Most banks will require you to provide an EIN or a Federal Tax Identification Number to open a business bank account. Some banks may allow Sole Proprietors to open a business bank account by using their Social Security number instead.