EIN: The Social Security Number Your Business Needs

An EIN (Employer Identification Number) is basically a Social Security number for your business. The IRS uses it to track your business the way your mom tracks your location — persistently and without your consent.

You need an EIN if you want to open a business bank account, hire employees, file business taxes, or generally be taken seriously. It's free to get from the IRS (yes, something from the government that's actually free), and it takes about five minutes online.

To apply, visit the IRS website (irs.gov/businesses) and fill out Form SS-4. You'll need your legal name, business name, address, and entity type. If you apply online during business hours (7am-10pm ET), you'll get your EIN immediately. It's faster than ordering a pizza.

Common mistakes people make: applying with the wrong entity type, forgetting they already have an EIN (yes, people do this), and thinking they need a lawyer to get one. You don't. Your golden retriever could probably do it if he had thumbs.

One important note: if you're a single-member LLC, you technically don't need an EIN for tax purposes — you can use your SSN. But you should get one anyway because giving your SSN to every vendor and bank is like posting your diary on Twitter. Get the EIN. Protect yourself.

Store your EIN somewhere safe. You'll need it for everything from bank accounts to tax filings to that one form you forgot about until the deadline.