If your images are for business, and they are delivered by download, our current understanding is, no
The exemption is available when the images are used exclusively for business; it is not available for prints, images transferred on physical media, or images for personal use. The rules change periodically. We no longer are required to keep an exemption form on file as long as the images are licensed and we state that in an invoice, contract, or license. All of our business clients get a license stating their usage rights.
More information on this the State of Washington's site
. If the link doesn't work, it probably means they moved it again.