Employers must generally inform staff about any monitoring arrangements and should, through proper consultation, take account of any objections that staff have to those arrangements. However, employers who can justify monitoring on the basis of a properly conducted impact assessment do not generally need the consent of individual workers. To the extent that consent is needed, employers tend to include a written term in the contract of employment, so that employees 'consent' to the monitoring when they sign their contract.

Even if workers freely give their consent, the employer should still conduct a proper impact assessment to make sure that the monitoring is necessary and justified and that any negative effects are outweighed by the benefits that the monitoring arrangements will bring. The General Data Protection Regulation (GDPR) strengthens the need for this impact assessment.

Clearly express informed consent is required where an employer sets out to collect sensitive data (for example, information about workers’ health) through monitoring.

There is an exemption to allow employers to collect data to monitor equality of opportunity, as long as the exercise is carried out in a way that safeguards privacy (usually done by anonymising the results).