Why ZIP Codes are strings
ZIP Codes are not used for arithmetic. Numeric database, CSV, or spreadsheet types can remove leading zeros common in the Northeast.
Consistency and verification
State examples support format and regional consistency tests. They do not mean a specific street address has passed USPS delivery verification.
Currently supported states
ALAlabamaMontgomery 36104AKAlaskaJuneau 99801AZArizonaPhoenix 85007ARArkansasLittle Rock 72201CACaliforniaSacramento 95814COColoradoDenver 80203CTConnecticutHartford 06106DEDelawareDover 19901DCDistrict of ColumbiaWashington 20004FLFloridaTallahassee 32399GAGeorgiaAtlanta 30334HIHawaiiHonolulu 96813IDIdahoBoise 83702ILIllinoisSpringfield 62701INIndianaIndianapolis 46204IAIowaDes Moines 50319KSKansasTopeka 66612KYKentuckyFrankfort 40601LALouisianaBaton Rouge 70802MEMaineAugusta 04330MDMarylandAnnapolis 21401MAMassachusettsBoston 02133MIMichiganLansing 48933MNMinnesotaSaint Paul 55155MSMississippiJackson 39201MOMissouriJefferson City 65101MTMontanaHelena 59601NENebraskaLincoln 68508NVNevadaCarson City 89701NHNew HampshireConcord 03301NJNew JerseyTrenton 08608NMNew MexicoSanta Fe 87501NYNew YorkAlbany 12207NCNorth CarolinaRaleigh 27601NDNorth DakotaBismarck 58505OHOhioColumbus 43215OKOklahomaOklahoma City 73105OROregonSalem 97301PAPennsylvaniaHarrisburg 17120RIRhode IslandProvidence 02903SCSouth CarolinaColumbia 29201SDSouth DakotaPierre 57501TNTennesseeNashville 37243TXTexasAustin 78701UTUtahSalt Lake City 84103VTVermontMontpelier 05602VAVirginiaRichmond 23219WAWashingtonOlympia 98504WVWest VirginiaCharleston 25305WIWisconsinMadison 53703WYWyomingCheyenne 82001