How will you monitor fare payment? Metlink ‘Transport Officers’ will be present onboard train services to regularly check those paying with Snapper have successfully tagged on, using a handheld device. This device cannot tag-on a Snapper card onboard, it only confirms if a card has already tagged on at a card reader. You must tag-on using the Snapper card readers on the train platform before boarding. If you forget your Snapper card or don’t have one, you can still pay with cash or use paper tickets. More information on this is available here.