When you apply for an EIN, the IRS will ask if your business will have employees. If you say yes, they'll enroll your business in the Electronic Federal Tax Payment System (EFTPS).
Enrollment enables you to make deposits by phone or online 24 hours a day, seven days a week. However, you have to wait for your EFTPS confirmation and PIN to come in the mail before you can do so. It should arrive within a few days.