8. What if I sign a 'Form 4' with an agent who shows me a flat, and later, I buy the flat through another agent or directly from the vendor?

In that case, you must also pay a commission to the first agent. See Schedule 3 - Commission to be paid by Purchaser in your estate agency agreement ( " Form 4 "). If you anticipate possible dealing with the vendor directly or another agent, then you can shorten the validity period in your agency contract so that you can appoint another agent afterwards.