Dynamics 365 has the most intricate user licensing model in the Microsoft estate, and the intricacy is exactly where the overspend hides. A single user can be licensed as a full user on one application, an attach user on others at a steep discount, a team member for light read and write tasks, or as an operations activity user. The base and attach structure rewards estates that map each user to the cheapest license their actual work justifies and quietly penalizes those that put everyone on a full user license by default. The most common pattern we find is an estate paying full base prices for users who touch a second application only lightly, when attach licensing would cover that access at a fraction of the cost, alongside full users doing work a team member license would have covered. Rationalization is the disciplined exercise of matching the license to the role, and on a large Dynamics footprint it routinely removes a fifth to a third of the annual user spend.
The Dynamics 365 model gives you several user license types at very different price points. Rationalization starts with understanding what each one entitles a user to do, because the gap between them is the gap between paying for a role and paying for a job title.
A user's first full application license is the base, priced at the full rate for that application. Every user who needs full access to at least one Dynamics application carries one base license. The base is the anchor of the model, and the error is treating it as the only license a multi application user needs.
Once a user holds a base license, additional full application access is available as an attach license at a steep discount to the base rate. A salesperson with a base license on Sales who also works in Customer Service should hold an attach license on the second application, not a second base. This is the single largest source of recoverable Dynamics overspend.
For users who only read data and perform light, bounded tasks, the team member license costs a small fraction of a full user. Its rights are deliberately limited, so it suits genuine light users rather than power users. Matching real light users to it, and only them, is where the second tranche of savings sits.
Dynamics overspend is rarely one large error. It is three recurring mismatches between the license a user holds and the work they actually do, each multiplied across the user base.
The costliest. A user who works across two applications carries two full base licenses because no one applied the attach discount to the second. Across a sales and service organization where many users touch both, this single mismatch can account for a large share of the Dynamics bill, and it persists because the base on each application looks individually correct.
Users provisioned with full base licenses who only view records, update a field, or submit the occasional request. Their actual usage is squarely within the team member rights, but they sit on a full user license because that was the default at onboarding. The license never gets revisited as the role settles into light use.
The mirror exposure. Users on team member licenses who have grown into power user tasks the license does not permit. This is a compliance risk rather than overspend, and it is the reason rationalization has to run in both directions: cheaper licenses where work is light, correct licenses where work has outgrown the entitlement.
The correct rationalization position maps every Dynamics user to the cheapest license their genuine usage justifies, applies the attach discount everywhere a user spans applications, and corrects the team member users who have outgrown the license. The exercise is grounded in usage data, not job titles.
We pull the actual usage of every Dynamics user across every application and rebuild the license assignment from that data. Multi application users move to one base plus attach licenses, capturing the discount on every application beyond the first. Full users whose usage sits within team member rights step down to the team member license. The recovered annual spend is direct and recurring, and on a large multi application footprint it commonly reaches a fifth to a third of the Dynamics user line, because the double base pattern and the over provisioned full user pattern usually coexist across the same population.
Rationalization that only steps users down creates compliance risk, so we run it in both directions. Team member users whose usage has grown into full user territory are moved to the correct license before an audit finds them performing work the team member entitlement excludes. The result is a user base where every license matches the work, which is both the cheapest defensible position and the one that survives a Dynamics licensing review without findings. We also set the review cadence so roles that drift are caught at the next cycle rather than at the next audit.
The base, attach, and team member structure, the three mismatches that inflate the bill, and the usage based mapping that puts every user on the cheapest license their work justifies. Sent on request.
We rebuild the Dynamics user license assignment from real usage data, apply the attach discount across every multi application user, step the over provisioned full users down to team member, and correct the team members who have outgrown the license. The user line comes down and the estate passes a Dynamics review without findings.