NomadOS

Legal · Compliance sources

Compliance sources

Every number NomadOS shows you traces back to a public regulation or an official dataset. This page lists what we use, who publishes it, and when we last refreshed it.

Last updated · April 25, 2026

1. Principles

NomadOS is a deterministic compliance engine wrapped in an editorial UI. Three rules govern every figure on the product:

  • Source-first. Every rule traces back to a named regulation, treaty, or official authority. We do not synthesise compliance facts.
  • Deterministic math. Limits like Schengen 90/180 and the 183-day window are computed from your trip ledger by the rules engine — never estimated by AI.
  • Verifiable. Each cell can be drilled down to its publisher and last-verified date. If a source is unavailable, the surface says so.

Important. NomadOS is an informational tool, not legal, tax, or immigration advice. Always verify critical decisions with a qualified tax advisor or immigration lawyer before acting.

2. Schengen 90/180

The Schengen ledger implements the rolling 180-day window defined in the Schengen Borders Code and follows the calculation methodology published by the European Commission.

  • Regulation (EU) 2016/399 — Schengen Borders Code, Art. 6. Defines short-stay limits for third-country nationals. EUR-Lex.
  • European Commission — Short-stay calculator. The reference implementation for the 90/180 rolling window. NomadOS reproduces its day-counting convention exactly. ec.europa.eu.
  • Practical Handbook for Border Guards. Operational guidance used by Schengen border officials; informs how partial-day stays and same-day transits are counted. Home-Affairs DG.

3. 183-day tax residency

The 183-day surface is an indicator, not a final residency decision. National rules vary widely (centre of life, habitual abode, treaty tie-breakers); we calibrate the indicator to OECD conventions and flag deeper checks when needed.

  • OECD Model Tax Convention, Art. 4. Defines residency and the tie-breaker hierarchy used by most bilateral tax treaties. oecd.org.
  • OECD Commentary on Article 15(2). Source of the "183 days in any 12-month period" convention adopted by most EU member states.
  • National tax authorities for country-specific exceptions (e.g. BMF/AO guidance on residence (Germany), HMRC Statutory Residence Test guidance (UK), IRS (US — Substantial Presence Test)). Country profiles cite the relevant national source inline.

4. Visa & entry rules

  • IATA Travel Information Manual (TIM). Industry-standard reference for visa, passport and health requirements; cross-checked against the issuing country's official portal.
  • EU EES & ETIAS portals. Official rollout schedules and operational details for the Entry/ Exit System and the European Travel Information and Authorisation System. travel-europe.europa.eu.
  • Embassy & consulate publications for digital-nomad visas, long-stay visas and country programmes. Each visa tab cites the issuing authority and the last-verified date.

5. Country intelligence data

Each country profile follows a fixed eight-tab schema (Overview, Entry & Visa, Finance, Climate, Quality of Life, Infrastructure, Living, Essentials). Every cell is source-attributed.

  • Cost of living & housing: Numbeo, Wise, OECD Better Life Index — cross-referenced and normalised to USD.
  • Climate: NOAA, ECMWF / Copernicus, national meteorological services.
  • Safety & risk: OSAC, UK FCDO travel advice, the Global Peace Index. Travel advisories are cited per country and per refresh date.
  • Infrastructure & connectivity: Speedtest Global Index, ITU broadband statistics, national regulator data.
  • Healthcare: WHO Global Health Observatory, the Health Care Index, country health ministries.
  • Macro & demographics: World Bank Open Data, IMF, UN Population Division.

Where a public dataset is unavailable, the cell is marked "Source unavailable" rather than back-filled with a guess.

6. AI explanations

The AI assistant explains results in plain language but never invents compliance facts. It is constrained to:

  • Read computed numbers from the deterministic rules engine and country dataset.
  • Cite the same sources listed on this page when asked for provenance.
  • Decline or escalate when a question requires legal, tax or immigration advice — and recommend a qualified professional instead.

7. Data freshness & refresh cadence

  • Schengen rules: reviewed on every EU Schengen Borders Code amendment (next scheduled checks: EES rollout milestones).
  • Country profiles: on a rolling quarterly cadence; visa and entry-rule cells refresh more often when authorities publish updates.
  • Per-cell stamp:every data point on a country profile carries its own last-verified date in the UI; the disclaimer's "Last data refresh" value is the most recent platform-wide refresh.

8. Report a discrepancy

Spotted a stale source, a wrong link, or an outdated regulation? Email info@brandenburger-digital-systems.com with the country, the tab and the source you would prefer. We patch sources within five business days for compliance cells, and within the next regular refresh cycle for the softer datasets.

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