Home Office has no idea how many false matches will result from fingerprints with the ID card scheme
A great written question:
To ask the Secretary of State for the Home Department what estimate she has made of the number of false matches likely if fingerprint biometrics alone are used for the biometric verification for the identity card scheme after the enrolment of (a) one million, (b) six million, (c) 40 million and (d) 60 million individuals.
And the response:
The Identity and Passport Service is still in the process of procurement of specific biometric systems, hence we are unable to give an estimate of false matches that may occur. In the event of an uncertain fingerprint match the scheme will make use of human fingerprint experts to resolve uncertain fingerprint matches from the automated fingerprint matching system.
This procedure is used in all large-scale fingerprint systems to control false matches and the process will apply irrespective of the size of the database.
So the Home Office is going to have to consult fingerprint experts when, for example, you apply for a new passport or identity card and you happen to be falsely matched with other people on the database.