Topography of Singapore Postal Codes
Six digits take you from a corner of the island to one block of flats, and tell you whether it is a flat or a house.
Every address in Singapore has a six-digit postal code. Read it from left to right and it narrows down from a corner of the island to a single building. Along the way it also tells you whether that building is a block of public housing flats or a private home.
This map follows one code, 542264, digit by digit. It was inspired by Ben Fry’s zipdecode.
How six digits map an island
Scroll down to follow a postal code to its door.
From 1950, Singapore’s mail was sorted into 28 postal districts.
They never quite went away. Property listings still use them: D9 is Orchard, D10 is Bukit Timah and Holland, and D15 is Katong and Marine Parade.
In September 1995 the districts gave way to a 6-digit code. Today OneMap lists 121,515 postal codes across 141,839 addresses, in 83 sectors.
This map counts codes, not people. A tower of a hundred flats has one code, but a row of a hundred houses has a hundred. So the hottest patches are landed estates like Katong and Serangoon Gardens, and the big HDB towns look calmer than their crowds. The empty middle is the Central Catchment’s forest and reservoirs.
542264
The first digit already places you. 0 is the city centre. 1 to 4 ring it: west, centre, north-east and east. 5 to 8 reach out to the newer towns: 5 and 8 to the north-east, 6 to the west and 7 to the north.
012345678
542264
The first two digits are the sector. Sector 54 covers Sengkang and the landed streets around Kovan. It sits inside old District 19, along with sectors 53, 55 and 82, so the old map still lines up with the new one.
Let’s go down to street level. Every building with a sector 54 code turns orange as we arrive at Compassvale Bow in Sengkang.
542264
For public housing, the last three digits are the block number. These six towers are all Block 264.
542264
Six blocks can’t share one code, so the third digit tells them apart. 264A is 541264, 264B is 542264, 264C is 543264 and 264D is 544264. 264F is 540264 and 264E took 548264.
54?264
Zoom out and the other 54?264 codes aren’t blocks at all. 545264 is a house on Saint Anne’s Wood, and 546264, 547264 and 549264 are houses on Robey Crescent, Parry Avenue and Hendry Close.
When the third digit is 0 to 4, the code is usually an HDB block. When it is 5 to 9, it is usually a private home, and the last digits are no longer a block number.
Private homes are numbered street by street, and backwards. As the code climbs from 546000 to 549999, street names run from S down to B: Simon Place, Rosyth, Poh Huat, Parry, Leith, Kovan, Jansen, Hillside, Florence and finally Boundary Road.
546000 …
Try it yourself!
Type your own postal code below, one digit at a time, and watch it narrow down. You can drag the map, too.
Postal Code Explorer
… postal codes shown.