It is certainly sensible to share the right amount of information well before day 1. This expedites the integration process, since a significant amount of planning can be done in advance. We had employed a “Clean team”, and it worked out well for us. It is a good practice to employ such a team, which is generally a third party.
Since they are a neutral party, they have access to confidential data and information from both sides. Both the acquirer and the target (or the two merging companies in case of a merger) share information only through this team. The clean team will sift through this information, remove anything that is confidential, and pass on the rest to the other side. This ensures too much information is not shared. Of course, the legal teams of both sides also need to approve the information being shared, since sharing too much might violate anti-competition laws.
