Property ID Changes and Redirects

HelloData maintains a consistent property identifier (id) for each building to allow users to retrieve full property details and history. However, in rare but important edge cases, these IDs can change.

When Do Property IDs Change?

We may update the property ID you receive in the following scenarios:

1. Property Merges

When two properties (say A and B) are merged into one new property C:

• Both A and B will redirect to C.
• Your old id will still work and return property C.

2. Property Splits

When a property is split into multiple distinct properties:

• The old ID (e.g. A) will redirect to one of the resulting new properties (e.g. B or C).
• We recommend re-checking the address or building_name if you’re unsure.

3. Major Address or Identity Changes

If a property’s ZIP code, city, or address is significantly updated:

• We may assign a new ID to the updated property.
• The old ID will redirect to the new one.

Tips for Developers

• Use Search as Backup: If an ID returns unexpected results, confirm via the /property/search endpoint using name or address.
• Alias Matching: The building_name_alias and street_address_alias fields can help confirm that you’re looking at the right property.
• Cache Sensibly: Property IDs are generally stable, but if you rely on them long term, consider periodic revalidation.

Example

You originally fetched:

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GET /property/11111-11111-11111-11111
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{
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  "id": "22222-22222-22222-22222",
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  "building_name": "Main Street Apartments",
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  "building_name_alias": ["Main Apartments"],
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  "street_address": "1234 New Ave"
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}

This is expected behavior—you’re still seeing the correct property under the latest data we have. We redirect to the new ID to ensure you always get the most up-to-date information.