Adding 'AdBlue' to your vehicle is the driver’s responsibility as it won’t be covered as part of your service maintenance. To minimise nitrogen oxide emissions, regulations (Euro 6) were introduced that mean Diesel Exhaust Fluid ('AdBlue') is now added to vehicles. Typical consumption is around a litre of 'AdBlue' for every 600 miles, but this will vary between vehicles and driving style. An average tank size of 10 litres should last around 6,000 miles.
You'll get a dashboard warning light when your 'AdBlue' level starts to run low and your car’s handbook will tell you how to refill. If you run out, 5 litres should be enough.