A transmittal document is a "packing slip" for a document[which?] or collection of documents that are transferred from one company to another. The transmittal might be just the front page in an extensive document. But more often it is a separate document file that contains details of the documents that are sent. The transmittal also contains specific (company or project-related) details to help further processing of the documents for the recipient.

The content of the transmittal document depends on the situation. Some typical content in a transmittal can be:

• Date of the sending.
• Name details of sender/company and recipient/company.
• Project name, number(s), and other references to the project.
• Reason(s) for sending.
• Deadline(s) and/or descriptions of actions to be taken by recipient.
• Other status details.
• List of files sent: file name, size, type, revision number and other relevant metadata.
• Limitations, security measures or other dependencies of the document transmittal.

Transmittals are used in engineering and construction companies as a necessary tool in projects where a large number of documents are involved. Several document handling systems have functions for generating transmittal document along with packages of document for transfer.