Why Documentation Matters More Here Than in Normal Travel
If a country ever questions your tax status, the burden of proof is typically on you to show you genuinely weren't a resident — not on the tax authority to prove you were. Good records are what turn "I'm pretty sure I was under the threshold" into something you can actually demonstrate.
What to Keep, At Minimum
A day-tracking log. Every entry and exit date, for every country, kept in real time rather than reconstructed later from memory. A simple spreadsheet works; dedicated day-counting apps exist specifically for this and can be worth the small cost for the automatic rolling-window math alone (genuinely useful for the Schengen calculations covered elsewhere in this section).
Proof of location. Flight tickets and boarding passes, accommodation receipts or lease agreements, and credit card statements showing geographically-tagged transactions. These corroborate the log rather than replace it — a log with no supporting evidence is just an assertion.
Accommodation type records. Specifically relevant given the habitual-abode and available-dwelling triggers covered on the Beyond Schengen page — keep evidence that stays were genuinely short-term (booking confirmations, lease end dates) rather than open-ended arrangements that could be read as a standing home.
Income and business documentation. Contracts, invoices, and payment records showing where income is actually sourced from, which matters for the economic-ties and permanent-establishment triggers.
Tax filings, wherever required. If any country in your circuit does require a filing — including the US, which always requires one for citizens regardless of residency elsewhere — keep copies. A consistent filing history is itself a form of documentation that supports your overall position.
A Practical Habit, Not a One-Time Setup
The records that hold up under scrutiny are the ones kept contemporaneously — logged the week it happened, not reconstructed eighteen months later when a question comes up. Building a five-minute weekly habit (update the log, save the week's receipts) is far more reliable than planning to reconstruct everything later from memory and old emails.
Where to Go Next
→ Risks and Edge Cases — the situations where even good documentation doesn't fully resolve the underlying ambiguity.