Do I need documents to connect a number? If yes, what are they?

Document required for connecting virtual numbers depend on the country and type of number. Some numbers do not require documents. For others, you can use documents (passport or ID card) of any country. There are numbers that are connected only with local documents (documents of the same country the number comes from) and/or with proof of a local address (address in the same country or city as the number).
You can check the requirements for the documents in the article: "What countries require documents for further virtual number connection?".