An Employer Identification Number (EIN) is essential for registering sales tax in Maine because it serves as the business's federal tax identification number, uniquely identifying the entity to the Internal Revenue Service (IRS). The EIN is required for various business activities, including:

• Tax Registration: The MRS requires an EIN to process the sales tax registration application, linking the business to its tax obligations.

• Banking: An EIN is often needed to open business bank accounts.

• Hiring Employees: Businesses must use an EIN for payroll and employment tax purposes.

• Compliance: It ensures accurate reporting and remittance of taxes, facilitating compliance with both state and federal tax laws.

Without an EIN, businesses cannot complete the sales tax registration process in Maine, hindering their ability to legally collect and remit sales taxes on taxable sales.