Most vehicles require an MOT on the third anniversary of it's registration, that is, at three years old OR on the anniversary of its last MOT, it it's more than 3 years old. You can check the MOT status of your vehicle Here
The maximum amount a test station can charge depends on the type of vehicle you have. Currently, it is £54.85 for a car, and £29.65 for a standard motorcycle. There is no VAT due on MOT Testing Fees. To find out about the maximum charge for other vehicles, such as Vans and Taxis, Click Here
Most passenger cars with up to 8 seats fall under Class 4, Most Motorcycles (including those with a sidecar) with an engine smaller than 200cc fall under class one, and most large vans, such as LWB Transits, Sprinters and Crafters with a gross weight between 3000kg and 3500kg fall under Class 7. You can find the class of vehicle listed on your previous MOT under "Test Class", or by contacting your local testing station.
If your car fails (Over 36% of all Class 4 vehicles tested between 2015 - 2016 did), you will first be issued a "Refusal of an MOT test Certificate (VT30)". Depending on the severity of the failure, you can opt to leave the car with the testing station for repair - if it's retested within 10 working days, it will only require a partial retest and there is no fee payable for this.
You can take your car away for repairs, as long as you MOT certificate is still valid (Has not Lapsed). If it has lapsed, you are still allowed to take your vehicle to either have the failed defects fixed or a pre-arranged MOT test appointment.
If you take your vehicle back for a retest to the same test center before the end of the next working day for a partial retest, you will not be required to pay again - This only applies to a certain list of defects - Check here for more information