Does it also work if the questionnaire is a PDF or Excel

Excel and pdf are the standard, not the exception

Yes, this works with Excel and with pdf — those are precisely the two formats that most customer portals deliver. A questionnaire rarely arrives as a neat webform; usually it is an Excel export from a tool such as EcoVadis or a signed pdf form from a bank or insurer. The system reads the text of the questions, links them to the supply chain file and adds a suggested answer. With Excel this works via the cell structure, with pdf via text recognition — in both cases the recognition remains per question, not per document, so a messy format with merged cells or images of tables can miss the recognition of individual questions.

What differs in practice between the two formats is not whether it works, but how well the recognition hits. A pdf that is itself a scan of a completed form is more difficult for text recognition than a pdf with actual text in it. With Excel the risk is sooner that a question is in a separate tab, or that a question about for example the company's annual turnover is hidden in a cell with multiple sub-questions. In all these cases the customer sees during confirmation which answer is suggested for which question, and can respond yes or no per answer before it goes back to his customer's portal.

What the recognition does and does not cover

Questions that literally match a field in the supply chain file — such as the establishment address of the company or the number of employees — are recognized most reliably, in any format. Questions that are formulated as free text, with explanation or with a choice from multiple sub-items in one cell, more often require manual verification. That is not a limitation of Excel or pdf in itself, but of how the questionnaire's author has formulated that question.