This page sets out exactly how the Millionaire Migration Index is calculated, so anyone can check or reproduce it from the published data. The current method is mmi-1.0.
The index measures relocation signals of wealthy people and business owners. It does not count millionaires: no public source records millionaires moving between countries, and estimates that claim to have been widely disputed. Every input here is an official or first-party record with a link to its source.
Key figures
- 4 signals in the UK edition (as of 1 October 2026)
- 10 smallest count published from Companies House data (smaller counts are withheld) (as of 1 October 2026)
- 124 destinations assessed in the latest edition (as of 1 October 2026)
- 21 destinations ranked in the latest edition (as of 1 October 2026)
Signals and weights (UK edition)
Signals, weights and windows
| Signal | Weight | Compared | Counts as hard evidence |
|---|---|---|---|
| British nationals controlling UK companies, resident in the country (Companies House) | 40% | latest month vs a year earlier | yes |
| First residence permits issued to UK citizens (Eurostat) | 25% | latest year vs previous year | yes |
| Residence-only first permits to UK citizens, the route used by most golden visas (Eurostat) | 20% | latest year vs previous year | yes |
| UK Google searches about moving there (leading indicator) | 15% | latest 12 months vs previous 12 | no (leading indicator) |
Source: Millionaire Migration Index method mmi-1.0
Companies House records the country of residence of every individual with significant control of a UK company. We match each person across companies by a keyed hash of their name and month and year of birth, never storing names, and count British nationals by where they live. Eurostat publishes residence permits issued to UK citizens by each EU and EFTA country; the residence-only reason covers financially independent people, including most golden-visa routes. Home Office visa data shows investor, founder and talent visas issued to people coming to the UK. Search volumes are a leading indicator of interest and carry the smallest weight.
The formula
For each destination and signal we compare the latest level L with the level a year earlier P:
- momentum m = ln((L + k) / (P + k)), where k is 10% of the median latest level across destinations for that signal, which damps jumps from small bases;
- each signal's momentum is standardised across destinations as a robust z-score, (m − median) / (1.4826 × median absolute deviation), capped at plus or minus 3;
- the score is 100 + 10 × (sum of weight × z-score) ÷ (sum of all weights), so a signal with no data counts as neutral and a destination with less evidence cannot reach the extremes.
A score of 100 means signals in line with the median destination. Business-owner and search signals use the latest month or the latest 12 months; Eurostat signals use the latest year.
Who is ranked
Minimum-data rules for ranking
| Rule | Threshold |
|---|---|
| Share of the total weight with data | at least 55% (two or more signals) |
| Hard-evidence signals | at least one (search alone never qualifies) |
| British business owners living there | at least 200 |
| Z-score cap | plus or minus 3 |
Source: Millionaire Migration Index method mmi-1.0
Destinations that fall short of these rules are still published in the data, but not ranked. A sensitivity table on each edition shows the rank under equal weights and without search signals, so readers can see how much the result depends on the weighting.
Privacy protection
Companies House data is processed on a temporary machine that is destroyed after each run. Only country totals leave it: counts under 10 are withheld and the rest are rounded to the nearest 5. The month-to-month state is a list of keyed hashes and residence codes, held for 40 days and never linked to names. No figure on this site can identify a person.
Known limits
Residence is self-reported to Companies House and can be updated late, often at the annual confirmation statement, so recent moves appear with a delay. Business-owner history before October 2026 is rebuilt from notification dates using each person's current residence, which understates how many lived abroad in earlier years; month-on-month moves are measured from October 2026. UK citizens appear in Eurostat permit data only from 2021, after Brexit, so no change is calculated across that break. Search volumes are rounded by Google and measure interest, not moves.
What changed since the last update
This is the first edition of this page; the next refresh will show what has changed.
How we calculate this
Corrections log: no corrections yet. Any correction to a published edition is listed here with its date.
Frequently asked questions
Why not count millionaires directly?
No public register records the wealth of people who move country. Estimates of millionaire migration rely on private models that cannot be checked. The index uses only records anyone can download, and labels what each one measures.
Why is the business-owner signal weighted most?
It is the only monthly, person-level official record of where people who run UK companies live, it covers every UK company, and it is updated as people report changes. It is the closest public signal to wealthy people relocating from the UK.
Can I reproduce the index?
Yes. Each edition publishes the inputs and scores as CSV. Applying the formula on this page to the published levels reproduces every score.
Will the method change?
Changes get a new method version, are announced on this page and in the next edition, and earlier editions keep the method they were published with.
Download the data
Download the tables as CSV (data as of 1 October 2026).
Related statistics
- Cheapest citizenship by investment 2026
- Countries with no income tax in 2026
- Golden visa countries and minimum investment amounts 2026
- How many millionaires in the UK? 2.43 million in 2025
- How many millionaires in the US? 23.6 million in 2025
- How many millionaires in the world? 57.5 million in 2025
- UK Company Formations Statistics 2026
- UK Sponsor Register Statistics 2026
Sources
- Companies House: persons with significant control snapshot
- Eurostat: first residence permits by reason and citizenship (migr_resfirst)
- Eurostat: first permits issued for other reasons (migr_resoth)
- Home Office: immigration system statistics data tables
- Google Ads search volumes via DataForSEO
- Millionaire Migration Index methodology
Contains public sector information licensed under the Open Government Licence v3.0 (Companies House PSC data). Contains public sector information licensed under the Open Government Licence v3.0 (Home Office immigration statistics). Source: Eurostat. Licensed under CC BY 4.0.
Updated 18 October 2026. This page is refreshed automatically when new data is published; figures carry the date they are true for. Permanent link: https://millionaire.news/millionaire-migration-index-methodology/
Last verified: 2026-10-18
