The routes listed here are our most frequently booked journeys, which means the pricing and the practical detail — typical distance, main roads used, usual traffic patterns — are already well established. That does not mean an unlisted journey is treated any differently: entering your exact pickup and drop-off on the booking page gives you a fixed fare for literally any route across the UK, calculated the same way as for a popular one.
Where a listed route helps most is in setting expectations before you book — roughly how far a journey like this usually runs, and what to expect in terms of timing. For a route that is not listed, the same fixed-fare principle applies, but it is worth allowing a little more room in your own planning simply because you will not have a reference point for typical journey time until you get your quote.
Regular routes, whether listed here or not, are also the easiest to set up on an account: if you find yourself booking the same journey repeatedly, a corporate or family account with the same driver requested where possible tends to work better than booking each trip individually.