What area is the SL1 postcode in?

SL1 is a postcode district in Slough, Slough, South East, England. It is part of the SL postcode area.

How many addresses are in the SL1 postcode?

The SL1 postcode district covers Slough in Slough. The exact address count can be retrieved via the APITier Postcode Lookup API.

How do I look up addresses in SL1 programmatically?

Use the APITier Postcode Lookup API: GET https://postcode.apitier.com/v1/postcodes/{postcode}?x-api-key=YOUR_KEY — where the postcode begins with SL1. The response returns all PAF addresses as structured JSON including building name, number, street, town, county, and geocoordinates.

Royal Mail PAF · South East

SL1 Postcode — Slough

SL1 is a postcode district in Slough, Slough, South East, England. Use the lookup below to explore addresses within this postcode district.

SL1

Postcode District

SL — Slough

Area

South East

Region

Royal Mail PAF

Data Source

Postcode Lookup — SL1 DistrictSample

{
  "_note": "Sample response — enter any postcode above and click Lookup for live data",
  "status": 200,
  "result": {
    "postcode": "SL1 1AA",
    "quality": 1,
    "eastings": 493464,
    "northings": 223415,
    "country": "England",
    "nhs_ha": "South East",
    "longitude": -0.6648,
    "latitude": 51.4632,
    "european_electoral_region": "South East",
    "primary_care_trust": "Slough",
    "region": "South East",
    "lsoa": "Slough 001A",
    "msoa": "Slough 001",
    "incode": "1AA",
    "outcode": "SL1",
    "parliamentary_constituency": "Slough",
    "admin_district": "Slough",
    "parish": "Slough, unparished area",
    "admin_county": "South East",
    "admin_ward": "Slough Central",
    "ced": null,
    "ccg": "NHS South East",
    "nuts": "Slough",
    "codes": {
      "admin_district": "E07000000",
      "admin_county": "E10000000",
      "admin_ward": "E05000000",
      "parish": "E43000000",
      "parliamentary_constituency": "E14000000",
      "ccg": "E38000000",
      "lsoa": "E01000000",
      "msoa": "E02000000"
    }
  }
}

About the SL1 Postcode District

The SL1 postcode district is part of the Slough (SL) postcode area, covering Slough and surrounding areas in South East, England.

Postcodes in the SL1 district follow the format SL1 nXX where n is a digit and XX are letters. Each inward code identifies a specific delivery walk within the district.

The wider Slough postcode area (SL) also covers: Windsor, Maidenhead, Eton, Burnham, Marlow.

Frequently Asked Questions

What area does the SL1 postcode cover?

The SL1 postcode district covers Slough in Slough, South East, England. It is one of 10 districts in the SL postcode area.

How do I look up all addresses in the SL1 postcode?

Use the live lookup widget above or call the APITier Postcode Lookup API: GET https://postcode.apitier.com/v1/postcodes/{full postcode}?x-api-key=YOUR_KEY. Replace {full postcode} with any complete postcode beginning SL1. The API returns all Royal Mail PAF addresses as structured JSON.

Is SL1 a valid UK postcode district?

Yes. SL1 is a Royal Mail postcode district in Slough, England. Full UK postcodes in this district follow the format SL1 followed by a digit and two letters (e.g. SL1 1AA).

SL1 Postcode — Slough

About the SL1 Postcode District

Frequently Asked Questions

Other Slough Postcode Districts