Financial checks are run against publicly available records, e.g. county court judgment records, IVA and bankruptcy filings and orders.
These checks do not involve looking at your credit score. They leave a “soft footprint” on your credit record which will have no effect on your credit score.
Most adverse credit information will not affect your screening. However, certain information must be relayed to your future employer, such as CCJs totalling over £10,000 or a bankruptcy. Some screening types require ANY adverse credit to be disclosed to the employer, no matter how low the amount. It is then your employer's decision as to whether they continue with your screening based on this information, so it is better to be open and honest about any adverse credit from the start. Any adverse information will be found during our searches whether you have disclosed it to us or not.