Sold Comparables API

The Sold Comparables API provides comprehensive access to recent property sales data from the UK Land Registry, enriched with Energy Performance Certificate (EPC) data. This powerful combination allows you to analyse property transactions with detailed information including floor area, energy ratings, and calculated price per square metre/foot.

This API provides:

• Recent property sales from the Land Registry (customizable time period)
• Complete transaction details: price paid, date, property type, estate type
• EPC data enrichment: floor area, energy ratings, estimated bedrooms
• Calculated metrics: price per m² and price per ft² for easy comparison
• Property characteristics: detached, semi-detached, terraced, flat, etc.
• New build and freehold/leasehold indicators
• Full address details for each sold property
• Results sorted by most recent sales first

This API is ideal for:

• Estate agents providing market analysis and property valuations
• Property portals displaying comparable sales to buyers and sellers
• Mortgage lenders assessing property values for lending decisions
• Property investors analysing market trends and investment opportunities
• Surveyors and valuers conducting professional property assessments
• PropTech platforms building automated valuation models (AVMs)
• Market research firms analysing local property market dynamics
• Homeowners researching their local property market

All requests to the Sold Comparables API require authentication using an API key. You can obtain your API key from your PropertyInsights dashboard after subscribing to an API plan.

Include your API key in the request header as follows:

X-API-Key: your_api_key_here

Base URL

https://propertyinsights.co.uk/api/v1/

/property/sold-comparables?postcode={postcode}&months={months}

Successful chargeable JSON responses include a top-level billing object. The endpoint examples on this page focus on the endpoint-specific data, so this repeated block may not be shown in every example.

"billing": {
  "mode": "prepaid",
  "creditsCharged": 1,
  "creditsRemaining": 1999,
  "creditsRefreshAt": "2026-08-14T09:30:00.000Z"
}

All authenticated API-key calls expose the billing headers, including validation errors and zero-credit status or management requests. Only successful chargeable JSON responses add the billing object to the response body.

All API responses are returned in JSON format. The standard response structure is as follows:

{
  "success": boolean,
  "data": {
    "postcode": string,
    "period": string,
    "totalResults": number,
    "comparables": [
      {
        "address": string,
        "postcode": string,
        "price": number,
        "transactionDate": string,
        "propertyType": string,
        "newBuild": boolean,
        "estateType": string,
        "floorArea": number | null,
        "energyRating": string | null,
        "estimatedBedrooms": number | null,
        "pricePerSqM": number | null,
        "pricePerSqFt": number | null
      }
    ]
  },
  "error": {
    "code": string,
    "message": string,
    "details": string
  } // Only present if success is false
}

{
  "success": true,
  "data": {
    "postcode": "SW1A 1AA",
    "period": "36 months",
    "totalResults": 3,
    "comparables": [
      {
        "address": "12, VICTORIA STREET, LONDON, SW1A 1AA",
        "postcode": "SW1A 1AA",
        "price": 875000,
        "transactionDate": "2024-11-15",
        "propertyType": "terraced",
        "newBuild": false,
        "estateType": "freehold",
        "floorArea": "145.0",
        "energyRating": "C",
        "estimatedBedrooms": 3,
        "pricePerSqM": 6034,
        "pricePerSqFt": 561
      },
      {
        "address": "8A, VICTORIA STREET, LONDON, SW1A 1AA",
        "postcode": "SW1A 1AA",
        "price": 1250000,
        "transactionDate": "2024-08-22",
        "propertyType": "flat",
        "newBuild": false,
        "estateType": "leasehold",
        "floorArea": "98.0",
        "energyRating": "B",
        "estimatedBedrooms": 2,
        "pricePerSqM": 12755,
        "pricePerSqFt": 1185
      },
      {
        "address": "THE COACH HOUSE, 5, VICTORIA STREET, LONDON, SW1A 1AA",
        "postcode": "SW1A 1AA",
        "price": 1850000,
        "transactionDate": "2023-05-10",
        "propertyType": "detached",
        "newBuild": false,
        "estateType": "freehold",
        "floorArea": "215.0",
        "energyRating": "D",
        "estimatedBedrooms": 4,
        "pricePerSqM": 8604,
        "pricePerSqFt": 799
      }
    ]
  }
}

{
  "success": true,
  "data": {
    "postcode": "SW1A 1AA",
    "period": "12 months",
    "totalResults": 0,
    "comparables": []
  }
}

Response Field Descriptions

PHP

<?php
$postcode = 'SW1A1AA';
$months = 36;

$url = "https://propertyinsights.co.uk/api/v1/property/sold-comparables?postcode={$postcode}&months={$months}";

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, [
    'x-api-key: YOUR_API_KEY'
]);

$response = curl_exec($ch);
curl_close($ch);

$data = json_decode($response, true);

if ($data['success']) {
    echo "Found {$data['data']['totalResults']} sales in {$data['data']['postcode']}\n";
    foreach ($data['data']['comparables'] as $property) {
        echo "{$property['address']}: £" . number_format($property['price']) . "\n";
        if (isset($property['pricePerSqM'])) {
            echo "  Price per m²: £{$property['pricePerSqM']}\n";
        }
    }
}
?>

The API uses standard HTTP response codes and returns detailed error information in JSON format. All errors follow a consistent structure to help you handle them appropriately in your application.

Error Response Format

{
  "success": false,
  "error": {
    "code": "MISSING_POSTCODE",
    "message": "Postcode parameter is required"
  }
}

API requests are subject to rate limiting based on your subscription plan. The current limits are:

When you exceed your rate limit, the API will return a 429 Too Many Requests response. Each response includes the following headers to help you track your usage:

X-RateLimit-Limit: [requests-per-minute limit]
X-RateLimit-Remaining: [requests remaining in current window]
X-RateLimit-Reset: [timestamp when limit resets]