[ESMA34-43-349 MiFID II Q&As on Investor protection Ch. 3, question 8]

In ESMA’s view, the scope of the requirements require firms to record the entirety of telephone conversations and electronic communications. This is because it is impossible to appreciate upfront whether the conversation will lead to the conclusion of a transaction. 

Therefore, ESMA expects firms to record all relevant telephone conversations or electronic communications from start to end.