How would you cope with a £19,000 mobile phone bill? Or a £33,000 water bill? How about a £500 bill for porn you never ordered or watched? Or a phone bill with so many zeros that you're not entirely sure how much the bill is for?
All these bills have been received in the last year - most of them in the UK. So what are the seven craziest bills, and how can you avoid a nasty surprise like this?
1. £750 for checking Facebook (the roaming risk)This bill emerged when Carphone Warehouse was researching how common it was to accidentally rack up big charges by checking social media sites when you're on holiday.
It came across Carly Woodgate, a 30-year-old mental health support worker from south west London, who regularly checked Facebook and Twitter while she holidayed in New York and was hit by a £750 bill when she returned.
The company warned that to avoid a surprise like this you need to check your data roaming charges, arrange to put a cap in place, turn off 'data-roaming', use local wifi rather than the 3G network, and avoid using data-intensive applications.
2. The £7,000 mobile bill (the downloading disaster)Chris Wilson, a decorator from Milford Haven, Pembrokeshire, was left reeling when he received his mobile phone bill for just one month from Orange. He had been charged £6,875. The company says that the incredible charges came from downloading TV programmes and films.
The company and the customer disagreed dramatically over the quantity of downloading he had engaged in. However, it raises a real risk.
If you are to avoid download disasters you need to understand your limits and your usage. You need to know roughly how much data you are using, and keep an eye on it during the month to ensure you don't risk going over your limits. If you discover your use is very high, it may well be worth opting for an unlimited data package.
3. £19,000 internet bill (the technical glitch)Chris Bovis, a 26-year-old builder from Tilbury in Essex, was cut off by Orange after it tried and failed to take £19,000, from his account. The company said it had been caused by unusually large amounts of data being downloaded through his mobile phone.
Investigations indicate that the sky-high charges were caused by a fault with his iPhone, which meant it started sending and receiving large amounts of internet data in error. Fortunately the company agreed to reduce charges to zero as long as Apple confirmed the fault.
There's very little you can do to stop a technical glitch. However, you can nip it in the bud if you keep an eye on your usage. You should have an idea of what you are using, and it pays to check a couple of times a month that your usage matches your expectations.
4. £33,000 for water (leaking on a meter)Ryan Bishop, a 29-year-old scaffolding firm owner from Peacehaven in East Sussex, faced a £33,000 water bill after 21.5 million litres of water leaked around his property, and he was billed through the meter.
Eventually the water company repaired the leak and agreed to waive the charges for water that had leaked into the ground, but it comes as a timely reminder that we shouldn't just let meters tick away in the cupboard under the stairs. We need to check them occasionally to be sure our usage matches our expectations.
5. £500 for downloading films (bamboozled by technology)Ron Hayward, 74, and his wife Ann, 71 from Reddish near Manchester, were charged £500 by Virgin Media, and the itemised bill reveals that this was largely caused by the live streaming of porn to their property. On some days they were billed for 14 of these films a day. The couple have no idea how or why this was happening, and the service has been turned off at the property.
It's hard to know what happened here, but it's worth considering whether you understand all the services you have signed up to. You may have bought a TV package, for example, but are you aware of everything in the package, and any additional charges?
If you don't know how something works, or how you could risk racking up large bills, there's an argument that you ought to get to know your technology, or steer well clear.
6. 12 quadrillion euros for phone calls (phone firm error)Solenne San Jose, from Pessac near Bordeaux, got quite a shock when she opened a telephone bill for almost 12 quadrillion euros - that's almost 6,000 times the country's annual economic output. It was a final bill, calculated manually, after she closed her account.
It was only after a few calls to the company that they finally admitted they had made a mistake in the bill printing process. To apologise for the shock, they also waived the actual outstanding sum of 117.21 euros.
This has happened in the UK before. In 2003, Brian Law of Huddersfield received a final gas demand - after not getting round to paying his £59 bill. Unfortunately a glitch (whereby a reference number appeared as the amount outstanding) meant the demand was for £2.3 trillion.
7. £35,000 on the speaking clock (no mistake)And finally, a shocking bill that was run up perfectly legitimately. Figures released under the Freedom of Information Act revealed that the Metropolitan Police spent more than £35,000 making 110,000 calls to the speaking clock in the last two years. The force also spent more than £200,000 calling directory enquiries.
A spokesperson defended the money spent, saying there were good reasons why officers might need the exact time, and that many didn't have direct internet access, so needed to use a directory service.
It's an impressive sum - which presumably would buy an awful lot of highly accurate wristwatches and copies of the phone book.