The deadline to file a W-9 form is not specific to any year, as it is a form that is usually requested by businesses or organizations to collect information from individuals or entities who may receive payments from them. The W-9 form is not submitted to the IRS but is provided to the requester, and it is generally recommended to submit the form as soon as possible when requested. However, each specific request may have its own deadline that will be communicated by the requester.