Each of the listings has a map, a brief description of the territory courtesy of wikipedia, and the address(es) to where mail was sent; see below for a discussion of the potential challenges for delivery:
| Territory | Location |
| Akrotiri and Dhekelia | Cyprus, Mediterranean Sea |
| Anguilla | Caribbean, North Atlantic Ocean |
| Bermuda | North Atlantic Ocean |
| British Antarctic Territory (BAT) | Antarctica |
| British Indian Ocean Territory (BIOT) | Indian Ocean |
| British Virgin Islands | Caribbean, North Atlantic Ocean |
| Cayman Islands | Caribbean |
| Falkland Islands | South Atlantic Ocean |
| Gibraltar | Iberian Peninsula, Europe |
| Montserrat | Caribbean, North Atlantic Ocean |
| Pitcairn, Henderson, Ducie & Oeno Islands | Pacific Ocean |
| Saint Helena, Ascension, & Tristan da Cunha including: | |
| Saint Helena | South Atlantic Ocean |
| Ascension Island | South Atlantic Ocean |
| Tristan da Cunha | South Atlantic Ocean |
| South Georgia & the South Sandwich Islands | South Atlantic Ocean |
| Turks and Caicos Islands | Lucayan Archipelago, North Atlantic Ocean |
discussion
For mail handling, British Overseas Territories are “overseas constituent countries” represented by the United Kingdom per Article 4 of the Universal Postal Convention of the Universal Postal Union. UPU regulations stipulate international mail sent to these countries by other member states should have the same priority as domestic mail – meaning they are delivered just the same as any other mail. However, direct mails to and from some of the territories by me in the United States may experience difficulties due to several reasons: United States Postal Service non-recognition of addressed territories, non-existence of actual post offices, and means by which mail is transported. Oh, and the United States is planning on withdrawing from UPU in October 2019.
Territories which are absent from the USPS “Index of Countries and Localities” are British Antarctic Territory, British Indian Ocean Territory, and South Georgia and the South Sandwich Islands. In practical terms, both the BAT and South Georgia mail is transported via the Falkland Islands; and from there, mail forwarded to its final destination by vessels of the British Antarctic Survey. BIOT is interesting in that despite non-recognition by the USPS, inbound mail is handled by the United States Postal Service and British Forces Post Office. BIOT outbound mail is routed via Singapore.
BAT and South Georgia, like BIOT, do not have a robust postal infrastructure, per se. They do have UPU numbers, so mail supposedly should flow to and from these locations.
Although Dr. La Porta’s study showed most mail dispatched to Western Europe returned within 90 days, this may not the be case with the more remote British Overseas Territories. Mail is forwarded to Ascension once a month from Saint Helena, which has mail airlifted to it from London via Johannesburg, South Africa twice a week. Also via Johannesburg – except by ship – Tristan da Cunha has mail exchanged nine times a year or every couple of months. Pitcairn, being the most remote of the oceanic territories is the outlier. Mail is transported to Pitcairn by ship via New Zealand four times a year – meaning the turn around time for “return to sender correspondence” may take well over six months.
However, all mail sent from my North Carolina address much first reach an international dispatch point – in the case of the East Coast of the United States, this is usually the postal facility at JFK airport in New York City. The service standard from my local post office to the international dispatch post office is at most five days. From there, mail is collected in “bags” and once a set weight is met, the bags are dispatched to locations overseas. Mail destined for delivery via the United Kingdom takes a far shorter time than mail destined for Iberian peninsula. This form is a handy reference for USPS transit times; the delivery map for domestic service is quite useful as well.
Please see the territory pages for a further discussion of other technical difficulties in sending incorrectly-addressed mail to each.
In addition to The Responses page, a running spreadsheet of addresses, dates sent, and dates received is here.
territories and postcodes
Mail sent to each of the territories includes the official postcode as issued by the Royal Post or the local postal authority. Despite an officially-assigned postcode, some territories include other identifiers in their address schemes to avoid incorrect routing of mail. Below, please find the official postcodes in force in 2019.
| Territory | Postcode |
| Akrotiri and Dhekelia (Akrotiri) | BFPO 57 / BF1 2AT |
| Akrotiri and Dhekelia (Dhekelia) | BFPO 58 / BF1 2AU |
| Anguilla | AI-2640 (?) |
| Ascension Island | ASCN 1ZZ |
| Bermuda | ll nn |
| British Antarctic Territory | BIQQ 1ZZ |
| British Indian Ocean Territory | BBND 1ZZ / BF 485 / BF1 4TG |
| British Virgin Islands | VG-nnnn |
| Cayman Islands | KYn-nnnn |
| Falkland Islands | FIQQ 1ZZ |
| Gibraltar | GX11 1AA |
| Montserrat | MSR-nnnn |
| Pitcairn Islands | PCRN 1ZZ |
| Saint Helena | STHL 1ZZ |
| South Georgia and the South Sandwich Islands | SIQQ 1ZZ |
| Tristan da Cunha | TDCU 1ZZ |
| Turks and Caicos Islands | TKCA 1ZZ |