Social Security Software

Social Security Reference Material

File Upload Compression

This information is for developers of payroll and tax reporting software who wish to enhance their products by incorporating the Internet business services provided by Social Security.

What is Business Services Online?

Business Services Online (BSO) is a suite of Internet services for businesses and employers who exchange information with Social Security. BSO users must complete a one-time registration process before using the system.

Connecting to BSO

Developers of payroll and tax reporting software can use Social Security processes to access the BSO and submit wage reports. The BSO Welcome Page is the single point of entry for all BSO users. Advise your customers that they will need Internet access and a web browser with 128-bit encryption and the ability to support cookies.

Developer Tips and Resources

• Provide a link to the Internal Revenue Service on the main menu of your application. This allows users to obtain filing instructions, extension request forms, and other publications.
• Provide processes for preparing wage-data files according to Social Security's Specifications for Filing Forms W-2 Electronically (EFW2) standards. The EFW2 format is for original (Form W-2) files and the EFW2C format is for correction (Form W-2c) files. Both the EFW2 and the EFW2C publications can be downloaded from the Publications & Forms page.
• Test your application created wage files through AccuWage Online to confirm compliance with EFW2/EFW2 standards.
• Automatically populate the User ID field in the RA/RCA record with the BSO User ID assigned to the person who is attesting to the accuracy of the file.
• Do not build submission files containing more than 1 million RW records or 50,000 RE records. If the employer needs to submit more than 1 million Forms W-2, develop your application to break them into smaller submission files.
• If the organization files on behalf of multiple employers, include no more than 500,000 RCW records or 25,000 RCE records per submission.
• Wage-data submissions must not span multiple files. Build each W-2 submission file beginning with an RA record and ending with an RF record, and each W-2c submission file beginning with an RCA record and ending with an RCF record.
• Provide a means to compress wage-data files before they are submitted to Social Security. Compressing large data files can dramatically reduce transmission time. Please use any compression tool that uses a standard "zip" file format. Compress each wage-file separately to prevent the compression of multiple wage files into the same compressed file.
• Establish an option or link to the BSO Welcome Page. This allows users to connect to the BSO Welcome Page to submit the wage file. Once users log into BSO, instructions are available for successful file submission.

More Information

If you would like more information, contact an Employer Services Liaison Officer. Contact information is available on the Customer Support page, or call 1-800-772-6270.