[ildon]

Lawyer here as well, but from Europe. Here the same is true, unless the government is involved.

Documents from/to any agency, including anything that has any tax relevance, - generally speaking (there are many caveats) - shall be signed with services compliant with the e-signature standards provided by Regulation 2014/910/EU (in short: PADES, CADES, XADES).

Out of curiosity: is there a similar requirement in terms of e-signature in the US when documents need to be sent to some agency, such as the IRS?