Maybe you can bring your experience in Britain to answer that, I mean what is the Britain gov strategy in dealing with that questions ? Some one in government may read this answers
It sounds nuts, but they've created a way of life where people just do things the right way. There are very few hurdles to setting up, you can do it all online, i started my own business, took me like an hour to do the paperwork, probably less.
They also use the stick as well too. There is a lot of regulation around finance. You can't make large purchases with cash, it has to be in an account. You make large deposits of cash and you're asked about it's source. irregular activity will see your bank account blocked as suspected fraud. most online transfers require multi factor authentication. If i want to say someone lent me money to buy a property, it can only be lent by a parent or a sibling, no cousins or aunts/uncles. They want bank records as proof.
If we take the example of undocumented income - after a certain point there isn't anything you can do with it. What do you do with £100,000 of cash? Most businesses won't take more than 2-5000 cash for a single transaction. Currency exchange guys require bank statements for large amounts or large volumes. They warn you that transactions will be blocked if too much is being sent to the same person, or the same account or from the same person. They have a £2000 limit before they require more documentation from you. Every single transaction at a currency exchange is linked to your ID. You have to start money laundering or commiting fraud to get large amounts of cash into the system. For all large transactions you need money in an account or access to finance.
They change the notes every 7-8 years too. old notes will still be valid for a good 2-3 years afterwards, so there is no sudden shortage, but it eventually forces all old notes out of circulation.
Also a big thing is the mindset of the people - we're taught to follow the rules.
Right now 90% of people consider the current covid regulations as nonsense. Despite that 90% of people also follow the rules too. That is how society functions, not by exceptionalism becoming the norm. Walk up to a zebra crossing on the road in the UK. it's just lines painted on the road, no cameras, no signals. If you set foot into it, oncoming traffic will stop until you have crossed the road. The rules state that the pedestrian has right of way on that section of road. Despite this people still cross cautiously, looking to see if incoming traffic has time to stop, if they look like they're slowing down. Also these crossings are placed in residential zones or commercial zones where there is low levels of traffic. There is consideration from govt, the people who designed the system, the drivers AND the pedestrians. That's why it functions so efficiently.
In the UK if you approach a roundabout you stop, look to your right until traffic is clear and then cross. You signal when you leave. In Pakistan, if you stop, the driver behind will crash into you "oye why did you stop in the middle of the road". You have to enter the roundabout and traffic is going in all sorts of directions, it's like a game of asteroids.
The mentality is different and it's key to the successful operation of this country.