Postcode areas 40XXX
- Postcode area 40000 Mont-de-Marsan
- Postcode area 40090 Saint-Perdon
- Postcode area 40100 Dax
- Postcode area 40110 Morcenx
- Postcode area 40120 Roquefort
- Postcode area 40130 Capbreton
- Postcode area 40140 Soustons
- Postcode area 40150 Hossegor
- Postcode area 40160 Parentis-en-Born
- Postcode area 40170 Saint-Julien-en-Born
- Postcode area 40180 Narrosse
- Postcode area 40190 Villeneuve-de-Marsan
- Postcode area 40200 Mimizan
- Postcode area 40210 Labouheyre
- Postcode area 40220 Tarnos
- Postcode area 40230 Saint-Vincent-de-Tyrosse
- Postcode area 40240 Labastide-d'Armagnac
- Postcode area 40250 Mugron
- Postcode area 40260 Castets
- Postcode area 40270 Grenade-sur-l'Adour
- Postcode area 40280 Saint-Pierre-du-Mont
- Postcode area 40290 Habas
- Postcode area 40300 Peyrehorade
- Postcode area 40310 Gabarret
- Postcode area 40320 Geaune
- Postcode area 40330 Amou
- Postcode area 40350 Pouillon
- Postcode area 40360 Pomarez
- Postcode area 40370 Rion-des-Landes
- Postcode area 40380 Montfort-en-Chalosse
- Postcode area 40390 Saint-Martin-de-Seignanx
- Postcode area 40400 Tartas
- Postcode area 40410 Pissos
- Postcode area 40420 Labrit
- Postcode area 40430 Sore
- Postcode area 40440 Ondres
- Postcode area 40460 Sanguinet
- Postcode area 40465 Pontonx-sur-l'Adour
- Postcode area 40480 Vieux-Boucau-les-Bains
- Postcode area 40500 Saint-Sever
- Postcode area 40510 Seignosse
- Postcode area 40530 Labenne
- Postcode area 40550 Léon
- Postcode area 40560 Vielle-Saint-Girons
- Postcode area 40600 Biscarrosse
- Postcode area 40630 Sabres
- Postcode area 40660 Messanges
- Postcode area 40700 Hagetmau
- Postcode area 40800 Aire-sur-l'Adour
- Postcode area 40990 Saint-Paul-lès-Dax