Away from avgas/mogas etc. and back to the OP:
The BBC article is well wrong.
The regs in the UK are very very complex, with some dating back to the 1920s.
A good, reliable summary is linked to from here:
Carriage and Storage of Petrol and Diesel | Regulations | Knowledge & Advice | Knowledge & Advice | RYA
As mentioned before, petrol stations can serve as little as the want - or not at all!
In many cases, to help stranded motorists and reduce staff training costs, they limit to one 5l plastic can. But that is usually their choice.
The 30l storage limit in a vehicle is for people who keep the stuff in their car: perhaps you live in a flat and can't keep it there and park on the street?
233l is quite a lot. We fill up to 10 20l jerry cans at our local supermarket. First, that is under the 233l. Second, the pumps stop at 100l and can only be used twice before you have to pay!
We spoke with the local petroleum officer before the petrol station opened, the supermarket's regional fuel manager on the day it opened (with the council chap standing with us) and the staff.
As the council chap said: we would rather have people who know what they are doing, doing it in a reasonable manner. At the self-service petrol pumps at midnight we have seen people on CCTV putting fuel in open buckets!