Rules are versioned facts
Tax thresholds, immigration residence periods and programme names change. ExpatEngine stores rules as structured facts tied to a period and source rather than treating one article as permanently correct.
Primary sources come first
Where possible we use tax authorities, immigration ministries, official government portals and legislation. Secondary professional summaries are useful for context but are not the preferred basis for a hard eligibility threshold.
What happens when a rule changes
A material change is reflected in the underlying data and the affected pages are regenerated. This avoids hand-editing dozens of disconnected articles that can drift apart.
How users should read dates
A tool result uses the rule set presented on the page. If your move spans a future tax year, remember that thresholds and rates can be indexed or amended before you arrive. Re-run the comparison closer to the move date.
Thresholds and durations are reviewed separately
A programme can remain active while its salary threshold changes every January. Conversely, a headline rate can stay the same while the eligibility definition changes. Storing those facts separately makes it possible to update the part that changed without rewriting an entire calculator.
The source link is part of the data
Each substantive scheme record keeps a link to the authority material used for the rule. That makes review faster and gives users a route to forms and definitions that do not belong inside a comparison tool. A page should be useful on its own, while the source remains available for procedural detail.
Near a change date, be conservative
If you are planning a move in the next tax year, treat a current-year threshold as a planning reference rather than a guaranteed future figure. Indexed salary tests, annual budgets and immigration amendments can change before your arrival. The closer the decision is to a new year or announced reform, the more important it is to re-run the comparison.
Avoid false precision
A tool can be exact about arithmetic and still be uncertain about law that depends on facts not entered. We prefer to expose the missing condition rather than convert it into a confident yes/no answer. That is especially important for prior-residence tests, employment classifications and permit categories.
Build a comparison you can revisit
Save the assumptions behind your result: gross salary, currency, planned move date, likely length of stay and which eligibility facts you have actually confirmed. Cross-border decisions often take months, and a comparison that looked obvious in January can change after a salary review, a new tax year or a different residence plan. Re-run the tool when one of those inputs changes rather than relying on an old screenshot.
Use official thresholds as hard gates
When a rule contains a salary, age, residence-history or day-count threshold, treat the official number as the gate. A rounded EUR conversion is there to make the number understandable, not to replace the legal currency or the authority’s definition. If you sit close to a threshold, leave a buffer and check how bonuses, unpaid leave or exchange-rate movements are treated.