Usually you don't need to declare this one year after paying the fine and it's usually illegal to discriminate against someone on this basis. The exceptions will be very clearly laid out in say a job application, where there are some jobs in healthcare, law enforcement, security services, finance, public transport, working with animals, where you will be asked to declare all criminal convictions and cautions. In this scenario they will often quote "Rehabilitation of Offenders Act 1974" since that is the legislation that guides this area, so if that legislation is mentioned, then there is usually a clear statement that spent convictions must be disclosed.
Now about 30% of males have a conviction, which I find bonkers in itself, and actually that legislation was intended to help people with convictions, so I wouldn't get too worried. There was, not that long ago, an attorney general with quite an eye-popping amount of speeding convictions. Employers - good ones at any rate - can and should take on people with relatively minor convictions without too much concern.