Multi-Level Territories

How overseas territories and autonomous regions are dual-modeled as both countries and state subdivisions, and how to query them correctly

Some geographical entities appear in this database at two levels simultaneously — as an independent ISO 3166-1 country and as an ISO 3166-2 subdivision of a parent country. This is not a bug; it reflects how the ISO standard itself models these territories.

Why Dual Modeling Exists

A handful of overseas or autonomous territories are listed by ISO 3166 at both levels:

• ISO 3166-1 assigns them their own two-letter country code (e.g. MQ for Martinique).
• ISO 3166-2 also lists them as subdivisions of a parent state (e.g. FR-MQ as a subdivision of France).

Martinique is an integral region of the French Republic — its residents vote in French national elections, use the euro, and are EU citizens — but it also has its own TLD (.mq), its own ISO codes, and independent representation in certain international contexts.

Both representations are kept in sync. Neither is canonical; both are first-class.

The 12 French Overseas Territories

ISO 3166-1	ISO 3166-2	Name	State type
GF	FR-GF	French Guiana	overseas region
PF	FR-PF	French Polynesia	overseas collectivity
TF	FR-TF	French Southern and Antarctic Lands	overseas territory
GP	FR-GP	Guadeloupe	overseas region
MQ	FR-MQ	Martinique	overseas region
YT	FR-YT	Mayotte	overseas region
NC	FR-NC	New Caledonia	overseas collectivity
RE	FR-RE	Réunion	overseas region
PM	FR-PM	Saint Pierre and Miquelon	overseas collectivity
BL	FR-BL	Saint-Barthélemy	overseas collectivity
MF	FR-MF	Saint-Martin (French part)	overseas collectivity
WF	FR-WF	Wallis and Futuna	overseas collectivity

Other Dual-Modeled Territories

The same pattern applies to territories of other countries:

Parent	Territory	countries.iso2	Notes
CN	Hong Kong SAR	HK	special administrative region
CN	Macau SAR	MO	special administrative region
US	Puerto Rico	PR	outlying area
US	Guam	GU	outlying area
US	American Samoa	AS	outlying area
US	Northern Mariana Islands	MP	outlying area
US	U.S. Virgin Islands	VI	outlying area
NO	Svalbard	SJ	arctic region

How to Query

Pick the model that matches the question being asked.

Everything in France (metropolitan + all overseas territories)

Use the FR country and traverse via state_id:

SELECT c.*
FROM cities c
JOIN states s ON c.state_id = s.id
WHERE s.country_code = 'FR';
-- includes all 12 overseas territories

Only Martinique (the territory in isolation)

Filter by the territory’s own ISO 3166-1 code:

SELECT * FROM cities WHERE country_code = 'MQ';

Metropolitan France only (exclude overseas)

Exclude the 12 overseas codes explicitly:

SELECT * FROM cities
WHERE country_code = 'FR'
  AND state_code NOT IN (
    'GF','PF','TF','GP','MQ','YT','NC','RE','PM','BL','MF','WF',
    '971','972','973','974','976'  -- INSEE codes for DROM
  );

The five DROM territories (French Guiana, Guadeloupe, Martinique, Réunion, Mayotte) currently use INSEE numeric codes (971–976) as their state_code, while the overseas collectivities use ISO 3166-2 alphabetic codes. A future update will align all to ISO 3166-2 alphabetic format.

JavaScript

import { getCitiesOfCountry } from '@countrystatecity/countries';

// All French cities including overseas territories
const allFrench = await getCitiesOfCountry('FR');

// Martinique only
const martinique = await getCitiesOfCountry('MQ');

// Metropolitan France only
const OVERSEAS = new Set(['GF','PF','TF','GP','MQ','YT','NC','RE','PM','BL','MF','WF']);
const metropolitan = allFrench.filter(c => !OVERSEAS.has(c.country_code));

Impact on API Responses

When you query /v1/countries, both MQ (Martinique) and FR (France) appear as separate entries. Both return valid states and cities. This is intentional — it ensures that code doing country_code === 'MQ' continues to work correctly.

If you are building country pickers or dropdowns, you may want to filter out the overseas territories from the top-level country list to avoid showing both “France” and “Martinique” as separate country options. Use the region/subregion fields or an explicit exclusion list.

Related

City Types

How the cities.type field works and how to filter to genuine settlements.

Database Schema

Full table definitions including level and parent_id fields on states and cities.