When a U.S. certificate is issued, an employee and employer copy will be sent to the
employer or a single copy to a self-employed person. It will be the responsibility
of the employer or self-employed person to present the certificate to the Spanish
authorities when requested to do so.
When a Spanish certificate is issued, the employer or self-employed person will be
provided with a copy. If the worker is employed, it is the responsibility of the employer
in the U.S. to retain the copy and to present it to IRS if requested to do so. If
the worker is self-employed, a photocopy of the certificate of coverage should be
attached to his or her tax return each year.