do I get the questionnaire back in the same Excel or PDF format as I uploaded it

Back in the same format as uploaded

Yes, that is the starting point: you receive the questionnaire back in the format in which you uploaded it, Excel remains Excel and pdf remains pdf. The system recognizes the questions in the file from your customer, fills in the answers from your supply chain file, and places them back where the question was. You therefore do not need to convert the file or retype it in a different template.

That is also necessary, because each customer has its own portal and its own layout. A list from a bank looks different from a list about AI use within service provision from an insurer, and both must ultimately fit into the portal where your customer expects them. What remains the same is the source: the same recorded data about for example the number of employees or the countries where the company has establishments are used again and again, only the packaging changes per customer. After filling in, you confirm each answer yourself with yes or no, and you submit the file to your customer's portal. So nothing changes in how you normally already work with that file, only the filling in itself is taken over.

This follows from the upload itself, not from a separate regulation

There is no law or standard that prescribes that a format must be retained — this simply follows from how the filling in works. The system reads the uploaded file, recognizes the questions in it and writes the answers back in the same structure. Sources such as the Trade Register Act 2007, the VSME standard or article 21(2) of the NIS2 Directive provide the content of the answers, not the form of the file. The form is determined by what the customer has submitted as a questionnaire.