Quick answer
Horizon's cost simulation engine models the full employer cost of a workforce move, gross-ups, allowances, policy tier, and worker classification included. Clone a scenario to change one variable, compare results side by side, then export a formal cost estimate with a field-level audit trail behind every number.
Every global mobility program eventually runs into the same wall: the spreadsheet. It works, until it doesn't. There's no version control, no audit trail, and no way to know which tab is the "real" number finance should be looking at. By the time a relocation budget slips, the move has usually already started.
Horizon by Topia was built to close that gap. At the center of the platform sits its cost simulation engine, the tool mobility teams use to model, compare, and finalize the true cost of moving people, before a single commitment is made.
What a simulation actually does
A Horizon simulation models the full employer cost of a workforce move, not just the headline salary, but everything underneath it: net-to-gross calculations, gross-ups, allowances, and the cost difference between an employee assignment and a contractor engagement.
Each simulation card gives you the essentials at a glance, origin, destination, total cost, cost per year, and assignment duration, so a mobility team can scan a portfolio of moves without opening a single one.
What you can model
- Employee assignments. Full origin-to-destination modeling with complete compensation detail.
- Contractor and freelancer scenarios. Compare worker classifications directly, side by side.
- Net-to-gross and gross-up calculations. Powered by Topia's proprietary tax engine.
- Housing, COLA, and allowances. Layered incrementally onto any base scenario.
- Group and project-based simulations. Batch analysis across an entire office expansion, not one move at a time.
A single relocation is a data point. Ten relocations tied to a Singapore expansion is a budget decision, and Horizon treats it that way.
Four steps to a decision
Horizon's simulation flow is intentionally simple, because the complexity should live in the calculation engine, not the interface.
- Set origin and destination. Select countries, enter compensation inputs.
- Run the calculation. Total employer cost, computed instantly.
- Clone and compare. Swap tax approach, package, or worker type.
- Export and share. Generate a formal cost estimate for stakeholders.
Step three is where Horizon earns its keep. Cloning a simulation takes seconds, which means an analyst can hold everything else constant and change exactly one variable, say, swapping an employee package for a contractor engagement, to isolate the real cost difference. No rebuilding formulas. No copy-pasting between tabs. Just a side-by-side comparison, generated on demand.
Built-in intelligence, not bolt-on features
What separates a simulation tool from a calculator is what happens around the numbers. Horizon layers several capabilities directly into every simulation:
- AI Agent integration. Ask about the tax and immigration risk of any move, in plain language, without leaving the platform.
- Policy-linked simulations. Tie a scenario directly to a Gold, Silver, or Bronze tier so cost modeling reflects actual program rules.
- Field-level audit trail. Every change tracked with a before and after snapshot, a permanent record of how a number evolved.
- Collaboration built in. Conversation notes with @mentions loop in finance or HR directly on a simulation.
- Formal cost estimates. Generate and export a polished, stakeholder-ready report in one click.
Try this
Prompt the AI Agent with a real scenario: "What are the tax and immigration risks of sending an employee from the US to Germany for six months?"
Horizon's AI Agent combines Topia's proprietary tax engine and immigration library with real-time reasoning, grounded in the platform's actual data, not a generic answer. As policies get configured, that reasoning increasingly reflects the organization's own risk appetite.
Example scenarios
Three patterns come up constantly in mobility planning, and Horizon's simulation engine is built around exactly these.
- US to Germany relocation. Full package versus localized, comparing total employer cost across both approaches.
- Singapore office expansion. Group simulation across ten moves, batch cost analysis under a single project.
- Employee versus contractor. Clone a simulation and swap the worker type to surface true cost differences.
Why it matters
Cost modeling in a spreadsheet has no memory. Once a number changes, the reasoning behind the old number is gone. Horizon's cost simulation engine keeps that reasoning intact: every clone, every comparison, every edit lives in an auditable record, linked to the policy and the employee it belongs to.
That's the shift Horizon is built around: cost modeling that isn't just faster than a spreadsheet, but structurally more trustworthy. A number a finance leader can stand behind in a board meeting, because there's a full trail behind it.
Want to see it run on your own numbers? Request a demo and we'll model a real move with you.
Frequently Asked Questions
- What does a Horizon cost simulation model?
- A Horizon simulation models the full employer cost of a workforce move, including net-to-gross calculations, gross-ups, housing and cost-of-living allowances, family size, and the cost difference between an employee assignment and a contractor engagement.
- Can you compare relocation scenarios side by side?
- Yes. Cloning a simulation takes seconds, so an analyst can hold every other input constant and change one variable, such as swapping an employee package for a contractor engagement, to isolate the real cost difference in a side-by-side view.
- Can Horizon model a group move or office expansion?
- Yes. Group and project-based simulations batch the analysis across an entire office expansion, so ten moves tied to one expansion are modeled as a single budget decision rather than ten separate spreadsheets.
- How does Horizon keep cost estimates auditable?
- Every change is tracked at field level with a before and after snapshot, linked to the policy and the employee it belongs to, so there is a permanent record of how a number evolved.
- What can the Horizon AI Agent answer about a move?
- You can ask about the tax and immigration risk of a specific move in plain language, for example sending an employee from the US to Germany for six months, and the agent reasons over Topia's proprietary tax engine and immigration library grounded in your platform data.
