zlacker

It's mandated by a sticker saying so. I don't think it's ever enforced.

A google seems to show that it is because the pumps are not certified to be accurate below 2 litres (or 5 litres for higher flow rate pumps like the HGV diesel pumps) so anything below this is at your own risk.

Another way of thinking about it is you have no right to complain if you think you've been short fueled if you don't dispense the minimum stated.

>>alexfo+(OP)
Exactly this, it's a legal requirement to show that under the weights and measures act I think.

Under that amount, you are likely paying much more per litre.