郵差的主要職責包括︰ (a) 執行派遞前準備工作、紮起、護送和收派郵件，包括實地以隨身配備的電腦設備輸入所需資料； (b) 分揀郵件及郵包，包括操作機械揀信系統及其他器材； (c) 內勤郵件處理，包括齊信、蓋銷郵件及操作電腦系統以發送郵件及郵包； (d) 以人手或用機器起卸及搬動郵袋及其他郵件；及 (e) 執行一般郵局櫃位職務。 此外，郵差必須穿著制服、輪班及/或超時工作，或須駕駛郵車。

A Postman is mainly deployed on – (a) preparation, bundling, mail escorting, delivery and collection of mail items, including onsite data input by using portable computer device; (b) sorting of mails and parcels, including operation of the mechanized letter sorting system and other postal equipment; (c) indoor mail processing, including facing and stamp cancelling of mails and dispatching mails and parcels using computer system; (d) loading, unloading and movement of bagged and other mails by physical handling or mechanical means; and (e) post office general counter duties. A Postman is required to wear uniform, to work shifts and/or overtime as necessary; and may be required to drive postal vehicles.