Financial Glossary
Form SS-4
Form SS-4 is the IRS application used to obtain an Employer Identification Number, the nine-digit federal tax identifier assigned to businesses, estates, trusts, and other entities. An EIN is required to open a business bank account, hire employees, file business tax returns, apply for licenses, and establish credit in the entity's name. The form collects information about entity type, reason for applying, responsible party, principal business activity, and expected number of employees. EINs can be obtained online instantly, by fax within days, or by mail over several weeks.
Problem & Application
A real estate investor forms a new single-member LLC to hold a short-term rental property. Even though a single-member LLC is a disregarded entity for federal income tax purposes by default, the investor still needs an EIN to open a dedicated business checking account, process guest payments separately from personal funds, and apply for a local lodging license. Filing Form SS-4 incorrectly -- for example, selecting the wrong entity type or naming a responsible party who is not a US person -- can require a correction process that delays account opening by weeks, pushing back the property's operating launch. When forming multiple LLCs across a portfolio, each entity requires its own SS-4 and EIN; a management spreadsheet tracking each entity's EIN, formation date, and registered agent prevents filing mix-ups at tax time.
In Short
Form SS-4 is a fundamental step in business formation, providing a unique identifier for tax purposes and enabling compliance with IRS requirements.