Well eventually businesses have to take their money into a bank (or similar), at which point any counterfeits will be removed and destroyed. The business therefore takes the hit and loses income, which means they also pay less tax. For a bus company, for example, I'd imagine it would be a significant problem.
Bus companies in the UK have big coin counting machines. The total cash at the end of the route is tallied off at the end of a route against the charge sheet from the ticket machine which is printed out. Rejected currency is seen as an operating cost and is handed back in crates to be disposed of. It's also why you see lots of bus companies giving huge discounts on pre-paid cards etc.
The annoying bit for is that if they accept a high percentage of bad currency this is tracked and the drivers get disciplined so they tend to try and give it back as change before the end of the route (which is why you'll sometimes see them fumbling around in a pocket for change rather than the coin dispenser fitted to the bus).
Therefore always check the change from a bus driver meticulously!
Also if you know a bus driver as a friend, watch your change too as the total amount handed back to the mint for disposal is usually less than the amount collected. Some of it gets stolen usually and pocketed by staff as it's still pretty easy to use in pubs etc.
Source: I used to write route management and payroll software for bus companies that tracked this sort of thing.
Buses I've been on in disparate areas of the UK [England, Scotland and Wales] have all [so far as I recall] had a coin receiving slot - you put the coins in, they are held between plates to enable counting. The drive activates a lever that deposits the coins (in a safe box behind the drivers security screen I think). The drivers don't get to touch the coins. No change is given.
I don't ride the bus very often, it's a bit too expensive. It seems either these are being phased out or you travel on buses in posher areas than I do.
I also rarely get on a bus, but I've never come across ones where the driver didn't touch coins in either Oxfordshire or Cambridgeshire (does make it sound like a posh area thing, but both have shitty areas that buses operate in too..) nor in London (which I think now requires tickets to be bought before boarding.. but could be wrong as I've only ever used my oyster card).
This was London. They still operate busses with trays almost universally and the driver gets to deal with the cash themselves. I've never actually seen that system in London - I have in Nottingham though. I don't tend to get busses now though :)
I used to work for Almex Control Systems who made bus to ket machines.
One of the problems we had was bus drivers who would push coins into the machine through gaps near the ticket printer.
This would short out something in the machine, allowing them to switch to hand written tickets which made it much easier to steal from the bus company.
I was always pleased that they used £1 coins and not, for example, paperclips.
Cool stuff. I worked with wayfarer kit. Absolutely indestructible by bus drivers by design. Right bunch of sods though bus drivers are. The worst class of "user" I've ever had to deal with.
Are the coins really checked / refused? I mean, I realise why that would happen (to prevent someone simply dumping their fake coins straight into their account), but I never thought the coins go through more than a sorting machine. Maybe there are more checks for businesses taking payments almost entirely in coins...
This provides some interesting incentives though... if you can sort the fake/real coins yourself in some way, you can deposit the real ones and use fake ones to pay all small bills (pay utilities, petrol, etc. with coins only)
