Request to increase Companies House API rate limit for contractor due diligence

API Enhancements
1

Hi

We are a Property Management Company that carries out due-diligence checks on contractors before they are added to, or retained within, our contractor database.

As part of this process, we need to validate a high volume of businesses against Companies House records. I have developed an internal application to support this work and keep our contractor information accurate and up to date.

In some review sessions, we may need to vet approximately 5,000+ contractors. Each contractor can require up to three API requests to obtain and verify the relevant company information, resulting in around 15,000 requests during a single session.

We understand that the current API limit is 600 requests per five-minute period. Our application has been designed to respect this limit by applying a global rate limiter: it pauses or slows requests as the threshold is approached and resumes once the five-minute window has passed. However, this creates substantial delays when processing larger contractor batches.

Would like to ask whether it is possible to:

  • increase the rate limit for our use case;
  • provide access to an appropriate higher-volume API arrangement; or
  • advise on the recommended approach for organisations carrying out legitimate, large-scale contractor verification.

The data is used solely for internal supplier onboarding, due diligence, and database maintenance within our property management operations.

We would be happy to provide further details about expected volumes, endpoints used, security measures, and the controls we have implemented to ensure responsible API use.

We would appreciate any advice on whether a higher limit can be granted or how best to support this volume of checking in line with Companies House API policies.

Thanks

2

Hi @darrenboland

Welcome to CH forum. CH do offer increased limits at their discretion, hopefully someone from their team will reply here asking you to get in touch.

If the increased limit is still not enough, the other option would be to download the bulk data Companies House data products - GOV.UK , which is made available free under Open Government license.

Basic company info is quite straight forward to extract and put in a database of yours, its just a giant CSV. If you need financial info to be extracted from the accounts, the XBRL parsing will need a pipeline to be setup, which is a significant task. I wrote a couple of blog posts about it here which describes my data pipeline https://medium.com/@fastukcompanysearch/how-i-built-an-ixbrl-converter-for-companies-house-e79be613d9dc

If all you need is basic company info (name, address, SIC Code etc), then the same bulk file can either be redownloaded and imported monthly, or it can be kept up to date by integrating with CH streaming data service. Not a weekend job by any means but by importing the bulk data you simply do away with the need to worry about the API limits.

Hope this helps