The big consumerbrand websites like McVitie's, Heinz and Warburtons always offer 0800 numbers, presumably because they are keenest to communicate directly with their customers, seeing it as part of their marketing.
Most other companies give the strong impression they don't want you to call them. You often have to scour numerous web pages to get anywhere near phone numbers, sometimes rejecting repeated exhortations to do your business online instead.
Companies which serve disproportionate numbers of customers from poorer demographics tend to offer more 0800 numbers. Asda is a good example, offering 0800 across the board except for calls to stores, which are local numbers.
The power companies are probably fond of 0800 for similar reasons. Scottish Hydro offers it for the vast majority of its services. Scottish Power and Scottish Gas mainly use it too.
Many other companies use a selection of numbers, often seemingly saving 0800 for the calls they want the most. Tesco uses it for customer service, online groceries and technical support. If you want to call the stores, it's 0345. If you want to call the phone shop, it's 0844, while Tesco Mobile is 0845.
Sainsbury's is 0800 for customer service and energy customers. But those enquiring about Nectar cards or ebooks must dial 0844, while Business Direct customers are 0870.
In many cases, the calls the companies want most are the ones where they sell you something. So if you call Aviva for an insurance quote, it's 0800. But if you call to make a claim or manage your policy, it's 0844.
Similarly, FedEx is 0800 if you're ringing for a quote. But if you want customer service, you call 0845 or a local number.
Many more companies avoid 0800 because they have to pay for the service, while still encouraging some numbers more than others. Calling the local Domino's Pizza for the Friday night Sloppy Joe is 0844. Should you have a more general customer service query, you call 0871. Pizza Hut is the same, only marginally more generous, with local stores on local numbers and customer service on 0844.
Ticketmaster is almost always 0844, save for special-needs callers on 0800, and it also handles the calls for many major football clubs,
Theatres like the Edinburgh Playhouse and the King's in Glasgow are centralised under ATG bookings, meaning 0844, while Odeon and Cineworld's film information lines are 0871.
Premier Inn might proudly claim to offer "quality hotel accommodation at affordable hotel prices," but calls to a particular hotel reception are on 0871. Customer relations is 0845. Travel Lodge uses 0871 for hotel receptions and central reservations. It's similar with travel firms such as First Bus, Virgin Trains, BA and agents such as Thomas Cook and Thomson, though none can match Ryanair, the only major consumer firm we researched that used a £1-per-minute 0905 number for priority assistance.
There are oddities. The British Heart Foundation is 0800 for retail customer service, and 0300 for medical information and other customers. But for some reason it's 0844 to call its furniture and electrical stores, and 0871 to order its magazine. RBS customers who have had their credit cards stolen must call an 0870.
Finally, special mention must be made of directory enquiries. Everyone knows this costs a packet, but the tariffs deserve repeating. BT's 118 500 is an automatic £0.59 connection fee then £2.39 a minute; 118 118 is a £1.59 fee plus £1.99. Think on that next time those daft moustached athletes put a smile on your face.