You are only able to extend your stay should you not have already purchased the maximum stay period.
If parking in a Start/Stop location you will automatically be allocated the maximum stay duration upon activating your parking and are required to de-activate your session when leaving. With Buy Time, you will be required to enter a duration upfront. If you then need longer than originally expected and you have not already selected to park for the maximum stay you will be given the option to extend your session when calling back, going on-line (including our mobile site) or using our mobile apps.
Should you not be offered the option to extend your current session then you have already reached the maximum stay duration at that location. This means that you will either need to purchase a new session or move your vehicle to another area to limit the potential of receiving an Infringement Notice. You should refer to local signage or search our Parking Locator tool for full details on the maximum stay period per location.