Postcode areas 31XXX
- Postcode area 31008 Elze
- Postcode area 31020 Salzhemmendorf
- Postcode area 31028 Gronau (Leine)
- Postcode area 31036 Eime
- Postcode area 31061 Alfeld (Leine)
- Postcode area 31073 Grünenplan, Delligsen
- Postcode area 31079 Sibbesse
- Postcode area 31084 Freden (Leine)
- Postcode area 31089 Duingen
- Postcode area 31134 Hildesheim
- Postcode area 31135 Hildesheim
- Postcode area 31137 Hildesheim
- Postcode area 31139 Hildesheim
- Postcode area 31141 Hildesheim
- Postcode area 31157 Sarstedt
- Postcode area 31162 Bad Salzdetfurth
- Postcode area 31167 Bockenem
- Postcode area 31171 Nordstemmen
- Postcode area 31174 Schellerten
- Postcode area 31177 Harsum
- Postcode area 31180 Giesen
- Postcode area 31185 Söhlde
- Postcode area 31188 Holle
- Postcode area 31191 Algermissen
- Postcode area 31195 Lamspringe
- Postcode area 31199 Diekholzen
- Postcode area 31224 Peine
- Postcode area 31226 Peine
- Postcode area 31228 Peine
- Postcode area 31234 Edemissen
- Postcode area 31241 Ilsede
- Postcode area 31246 Lahstedt
- Postcode area 31249 Hohenhameln
- Postcode area 31275 Lehrte
- Postcode area 31303 Burgdorf
- Postcode area 31311 Uetze
- Postcode area 31319 Sehnde
- Postcode area 31515 Wunstorf
- Postcode area 31535 Neustadt am Rübenberge
- Postcode area 31542 Bad Nenndorf
- Postcode area 31547 Rehburg-Loccum
- Postcode area 31552 Apelern, Rodenberg
- Postcode area 31553 Auhagen, Sachsenhagen
- Postcode area 31555 Suthfeld
- Postcode area 31556 Wölpinghausen
- Postcode area 31558 Hagenburg
- Postcode area 31559 Haste, Hohnhorst
- Postcode area 31582 Nienburg/Weser
- Postcode area 31592 Stolzenau
- Postcode area 31595 Steyerberg
- Postcode area 31600 Uchte
- Postcode area 31603 Diepenau
- Postcode area 31604 Raddestorf
- Postcode area 31606 Warmsen
- Postcode area 31608 Marklohe
- Postcode area 31609 Balge
- Postcode area 31613 Wietzen
- Postcode area 31618 Liebenau
- Postcode area 31619 Binnen
- Postcode area 31621 Pennigsehl
- Postcode area 31622 Heemsen
- Postcode area 31623 Drakenburg
- Postcode area 31626 Haßbergen
- Postcode area 31627 Rohrsen
- Postcode area 31628 Landesbergen
- Postcode area 31629 Estorf
- Postcode area 31632 Husum
- Postcode area 31633 Leese
- Postcode area 31634 Steimbke
- Postcode area 31636 Linsburg
- Postcode area 31637 Rodewald
- Postcode area 31638 Stöckse
- Postcode area 31655 Stadthagen
- Postcode area 31675 Bückeburg
- Postcode area 31683 Obernkirchen
- Postcode area 31688 Nienstädt
- Postcode area 31691 Helpsen, Seggebruch
- Postcode area 31693 Hespe
- Postcode area 31698 Lindhorst
- Postcode area 31699 Beckedorf
- Postcode area 31700 Heuerßen
- Postcode area 31702 Lüdersfeld
- Postcode area 31707 Heeßen, Bad Eilsen
- Postcode area 31708 Ahnsen
- Postcode area 31710 Buchholz
- Postcode area 31711 Luhden
- Postcode area 31712 Niederwöhren
- Postcode area 31714 Lauenhagen
- Postcode area 31715 Meerbeck
- Postcode area 31717 Nordsehl
- Postcode area 31718 Pollhagen
- Postcode area 31719 Wiedensahl
- Postcode area 31737 Rinteln
- Postcode area 31749 Auetal
- Postcode area 31785 Hameln
- Postcode area 31787 Hameln
- Postcode area 31789 Hameln
- Postcode area 31812 Bad Pyrmont
- Postcode area 31832 Springe
- Postcode area 31840 Hessisch Oldendorf
- Postcode area 31848 Bad Münder am Deister
- Postcode area 31855 Aerzen
- Postcode area 31860 Emmerthal
- Postcode area 31863 Coppenbrügge
- Postcode area 31867 Pohle, Lauenau, Messenkamp, Hülsede etc
- Postcode area 31868 Ottenstein