When are duplicate copies of patent correspondence required?

While the USPTO generally discourages filing duplicate copies, there are situations where separate copies are necessary. According to MPEP 502.04:

Since each file must be complete in itself, a separate copy of every paper to be filed in a patent, patent file, or other proceeding must be furnished for each file to which the paper pertains, even though the contents of the papers filed in two or more files may be identical.

This means that if a document relates to multiple patent applications or proceedings, a separate copy must be submitted for each relevant file, even if the content is identical across all copies.

To learn more:

• USPTO
• patent correspondence
• duplicate copies
• filing requirements