An ICP is a filter
An ideal customer profile should make prospecting decisions easier. If almost every business qualifies, the profile is too broad. Start with the characteristics that affect service fit and commercial value.
Define firmographic boundaries
Useful starting fields include geography, employee range, industry and number of locations. Add factors that matter to your delivery model, such as whether the prospect has internal IT, regulated requirements, cloud complexity or a distributed workforce.
Include commercial reality
The right prospect is not simply a company that needs IT. Consider whether the likely contract value, service scope and support requirements make the organisation commercially sensible for your MSP.
Write down exclusions
Exclusions are as useful as inclusion criteria. Existing customers, current opportunities, unsuitable sectors, organisations outside your coverage and businesses that are too small or too large should be removed before outreach.
Refine from evidence
Treat the first ICP as a hypothesis. Use campaign evidence to learn which types of organisations respond, qualify and progress. Adjust the criteria deliberately rather than broadening the list simply to increase volume.