Effective in 2010 for 2009 forms W-2 and W-2C, payroll companies and employers with 250 or more employees must electronically transmit the forms W-2 and W-2C using the Social Security Administration's EFW2 and EFW2C format. Employers who have fewer than 250 employees but wish to electronically file their employees' W-2s may also electronically transmit their employees' W-2s.
To register, visit our Electronic W-2 Program web page and click on W-2 Transmitter Registration. Once you have registered and received your credentials, you will be able to transmit your W-2s electronically.