Decide the organisation first. Uncertainty about roles paralyses integration. The leadership structure, reporting lines and the fate of overlapping positions should be decided and communicated as early as legally and practically possible — ideally in the first weeks.

Protect customers and cash. Integration consumes management attention, and customers notice. Assign explicit ownership for key accounts and service levels, and watch working capital closely: billing, collections and supplier terms often deteriorate during transitions.

Track synergies against the deal case. Every synergy in the investment case should have an owner, a baseline, a target and a date. Reporting progress monthly to the board turns an aspiration into a managed programme and surfaces problems while they can still be addressed.

Sequence systems behind decisions. Integrating systems before deciding how the combined business will operate locks in two ways of working. Decide the process and the organisation; then choose and integrate the systems that serve them.

Communicate more than feels necessary. In the absence of information, people assume the worst. A regular, honest cadence of communication to employees, customers and suppliers is the cheapest risk reduction available in an integration.