There are additional fields like "postalCode" and "phoneSuffix" that certain carriers need to authenticate your API request. Find the full list here.

Some carriers need to provide additional information about the tracking (to ensure that you are really the owner of the tracking information) in addition to the tracking number. These fields are handled differently by specific carriers.

Additional fields Format

postalCodePostal code of recipient address10001
phoneSuffixThe last 4 digits of the shipment sender's or recipient's phone number1234

Carriers that require additional fields

CarriercourierCodeRequired fields
Allied ExpressalliedexpresspostalCode
B2C Europeb2ceurope-bepostalCode
Colis Privecolis-privepostalCode
GEL Express Logistikgel-express-logistikpostalCode
GLS Spain (National)gls-spainpostalCode
Mondial RelaymondialrelaypostalCode
Postmedia Parcel Servicespostmedia-parcel-services-bni-papostalCode
The Delivery GroupthedeliverygrouppostalCode
XDP EXPRESSxdpexpresspostalCode
sfb2cSF ExpressphoneSuffix
jtexpress-mxJ&T Express (MX)phoneSuffix
jetidJ&T Express (ID)phoneSuffix