At this time of year, waiting times can be quite long at most test centres. When looking for a driving test at short notice, you may want to use a specialist company that continuously seeks driving tests at short notice (once you have already booked a test). There are a number of different Apps/websites offering such a service, charging around £20. Driving Test Genie claim to have the cheapest service, charging £17.99 (correct as of May 2019) but, by using this link, a £3 discount is applied (reducing the cost to you to just £14,99). However, please shop around for other offers and always read their terms and conditions.