The update service is an online subscription service that lets you keep your DBS certificates up to date and allows employers to check a certificate online, with your consent. Registration lasts for one year and costs £13 a year for those in paid roles (it's free for volunteers) and starts from the date your DBS certificate was issued.
The ECB will automatically register volunteers certificates with the Update Service when they make an application. This can be opted out of.
For a full guide on the DBS Update Service, visit https://www.gov.uk/government/publications/dbs-update-service-applicant-guide/dbs-update-service-applicant-guide