The SM postcode area, also known as the Sutton & Morden postcode area,[2][3] is a group of seven postcode districts in England, within five post towns.

The main sorting office is in Sutton, with outgoing mail being sorted at Croydon Mail Centre.

The area served includes most of the London Borough of Sutton, while most of SM4 covers the southwestern part of the London Borough of Merton.

Most of SM7 and a small part of SM2 cover the northern part of the borough of Reigate and Banstead in Surrey, while SM2 also covers the village of East Ewell in the borough of Epsom and Ewell.

The approximate coverage of the postcode districts:[2]