Revenue inspectors and officers mostly work at railway stations checking passengers' tickets as they board and alight trains, but can also be found on bus services. Inspectors may begin an investigation if they believe a passenger is travelling without a valid ticket, such as an adult travelling on a child ticket, an out of date or invalid ticket, or if the passenger has travelled beyond the destination printed on their ticket, with the intent to avoid their correct rail or bus fare. If the revenue inspector or officer believes there was intent to avoid payment, a penalty fare may be issued, or the passenger may be reported for prosecution. Inspectors usually wear a uniform provided by their employer..