TL;DR — Key Takeaways
- →Enter the move date, the salary, and both countries.
- →Income before the move and income after it are not taxed as one full year in the new country.
- →March and October produce different splits on the same salary.
- →Treaty relief and dual-status years can change the planning figure.
Short answer
Use the relocation date, not a full-year country compare, when you change country partway through the year. The months before the move and the months after are different slices of the same salary.
Domicyle Premium mid-year move calculator prorates where the dataset supports split-year treatment. The result is a planning number for a contract conversation. It is not a filed return, and a treaty can override the simple split.
Educational planning only — not tax advice.