A certified translation can validly be signed with an electronic signature, which is increasingly widely used and, importantly, it is environmentally friendly.
A translation certified electronically is a PDF document bearing a qualified signature of a sworn translator.
Such a document constitutes a fully valid certified translation.
I strongly promote the use of electronic signature for certified translations as it time-saving and environmentally friendly.
The electronic signature has a very solid legal foundation:
Act on the Profession of Sworn Translator of 25 November 2004 (consolidated text): Art. 18(1a) A sworn translator may, by means of a qualified electronic signature, certify a translation or a true copy of a document in electronic form.A true copy of a document may be certified in electronic form only on the basis of an original document, translation or true copy in written form.
Regulation (EU) No 910/2014 of the European Parliament and of the Council of 23 July 2014 on electronic identification and trust services for electronic transactions in the internal market and repealing Directive 1999/93/EC Article 78.1 of the Civil Code: § 1. In order to comply with the requirements of electronic form of legal transactions, it is sufficient to make a statement in electronic form and affix a qualified electronic signature to it. § 2. A statement made in electronic form is equivalent to a statement made in writing.
So do not hesitate to request an electronic signature on your certified translations.