back to article Psst, wanna block nuisance calls? BT'll do it... for a price

BT's latest phone, the BT6500, can prevent spammers from getting through to the harassed householder, forwarding them to an integrated answerphone - so BT still gets paid, of course. The householder will have to check those messages regularly though, as any caller withholding their Caller ID could end up there too, along with …


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  1. Phil O'Sophical Silver badge

    Phone spammers in this part of the world now use fake caller ID. The phone displays a number, but it it isn't actually assigned to anyone, and you can't ring it back. Internet searches for those numbers reveal hundreds of complaints.

    I'm certainly not 'the younger generation", but if I don't recognise the number I have no problem ignoring the call. If it is important they'll leave a message and I can either pickup, or call back.

    1. Badvok

      Echos my thoughts exactly. I can't imagine where BT get the idea this phone will manage to block 80% of unwanted calls, for me it would struggle to block 1%.

      Fortunately my family and I have pretty much got to the stage where I'm thinking of putting the land-line phone to silent mode and turning off the answering machine anyway.

    2. Lee Dowling Silver badge

      So the real question is, why does BT allow calls to come through with Caller-ID information that it can't verify is correct?

      Caller-ID is a pretty standardised technology and even uses different signalling in different countries. Which suggests that, at some point, the digital/analog conversions the call undergoes pass on that Caller-ID in a text format that can be verified or - if unverifiable - removed. Appropriate punishments for foreign telcos that fail to pass on accurate CallerID would probably be to just remove CallerID from any calls from them to this country (and vice versa), which I imagine would stuff up any number of systems and cause complaints.

      This would then allow BT to keep a whitelist of who is providing reliable CallerID (and thus trace spammers) and who isn't (and thus remove the CallerID and let people block unknown numbers as per usual).

      But it's all a scam. They know EXACTLY who called who from what number if they even need to know (i.e. police investigations), and they know exactly who to bill or not (or they wouldn't be able to make money). They just don't care because even an unwanted sales call makes them money the second its answered.

      I think they're picking at straws hoping people will sign up for this service, when they could do something similar in a SECOND on their network. Hell, why do I have to pay extra to block no-caller-id phone calls at all? Or even to SEE caller-id on a landline? It's all just about making money.

      And because of the way that they just don't care, my landline isn't with BT (it's cable), and isn't used anyway and the second I get spam calls on it from ANYWHERE (I have an answering machine of my own, so I'd know about them even if I was out as it logs the calls), I'll be complaining or removing that service from my account.

      Landlines are dead, for me because of years of spam on my parent's line that I couldn't block, and I imagine a lot of other people have similarly abandoned them. Hell, on my mobile if I get spam, I put it into a spam contact which has a silent ringtone (and about 12 numbers on it at the moment) and I *NEVER* hear from them again. I can't even do that on my landline without fiddling.

      Give me a landline with a service where I dial a number, and it reads the list of previous phonecalls, and lets me BLOCK THEM PERMANENTLY with one press, and where fake Caller-ID *CAN'T* propogate through to my line, and then we'll talk about how much extra I might want to give you for that. Until then, forget it.

      1. The obvious

        The short answer is that if you have two telco's or operate from more than one office or a block of lines, as pretty much every legitimate company with more people than fingers does, it's not possible to do what you propose via caller-ID. There are other signalling mechanisms which can be used to identify the callers entry point into the network but few companies (particularly BT) want to hand over the data to let us go direct to their call provider.

      2. dynamight

        So please enlighten me as to how BT, or any telco for that matter, can verify the accuracy of a CLI that originates in another network.

        1. Jamie Jones Silver badge
          Thumb Up


          I don't think they can (which your - I think - rhetorical question was alluding to)

        2. Phil O'Sophical Silver badge

          Validate CLI

          Well, strictly speaking CLI only refers to the info sent from your exchange to your phone, the network as a whole uses SS7 signalling, and that info is always available. Doesn't mean it's correct, of course. At best the most that a telco could do is verify that the information is correct for the network, i.e. if a call comes in from The Netherlands, but has SS7 data purporting to be from the UK, it could be dropped as fake.

          It's like email spam, some can be identified mechanically, a lot can only be guessed at heuristically, and the telcos seem to have no interest (i.e. they get no income) from putting effort into heuristics.

          1. Anonymous Coward
            Anonymous Coward

            Re: Validate CLI @Phil

            The problem being that multiple carriers will have had their mitts on that call.

            You only know who gave the call to you, not where they got it from. Reversing your example, if one UK operator receives a call from another UK operator, with signalling suggesting Netherlands origination, the call can't be dropped. It might have come from the Netherlands, it might not, but as the operator receiving the call I have no idea.

            It's not an impossible problem to solve but it would be an expensive and time-consuming one. The ITU would need to get all telcos and national bodies to agree to a new signalling authentication mechanism in a world where half the PSTN kit out there is obsolescent and the other half was made by people who've gone bust.

        3. P. Lee Silver badge

          Call routing information (where did your telco receive the call from) is the proper way to do it, (which I suspect could be provided with voip systems) due to the problems with CLI.

          But then, why would a telco want you to reject a call? That's just lost revenue.

          Until a disruptive player comes in, we're out of luck.

  2. Cannorn


    Is all but useless at the moment and running the phone system for a multinational PPI sales calls are the bane of my life at the moment and reflect a huge % of the voicemail storage capacity as the automated records call 1000's of our users dozens of times a day from withheld or otherwise disguised numbers that are impossible to even get enough info on to submit a Complaint to TPS with (not that they'll be UK based anyway)

    What we need is a phone that can detect these recorded messages, navigate to a human (why yes I'd LOVE PPI monies!) then transmit a frequency through the far handset that will melt the sales drones brains out their no.....oh...wait nvm...just seen the flaw in that plan....

    1. Richard Taylor 2 Silver badge


      A flaw?

      1. Number6

        Re: Ummm

        I suspect it was the reference to a brain...

    2. Dan 55 Silver badge

      Re: TPS

      AAISP did something similar (apart from the frequency)... click

      1. Parax
        Thumb Up

        Re: AAISP Honeypot

        I prefer this one

        1. Dave 126 Silver badge

          Re: AAISP Honeypot

          In "Greetings! Carbon-based Bipeds!" (collected essays), Arthur C Clarke outlined his plan to hack his fax machine so as to cost the senders of spam faxes money: IIRC, it amounted to manipulating packets so the sending machine would keep trying to send spam in vain.

    3. Badvok

      Re: TPS

      Or maybe we need a regulator with the balls to enforce some rules on the use caller-id.

    4. Anonymous Coward
      Anonymous Coward

      Re: TrueCall

      “What we need is a phone that can detect these recorded messages, navigate to a human (why yes I'd LOVE PPI monies!) then transmit a frequency through the far handset that will melt the sales drones brains”

      In the interim, you could always try buying a TrueCall filter.

      I blame people who answer their own phones. Anyone who doesn't have a butler or valet to do that sort of thing for them is one of life's pathetic failures.

      1. LateNightLarry
        Paris Hilton

        Re: TrueCall

        I want one that will work with my cell phone lines...

        Paris, just because I need some eye candy...

  3. g e


    Just register your phone no's with the Telephone Preference Service (and your postal address with the Mail Preference Service, too, while you're at it)

    They've reduced junk via either method by over 99% for free.

    And how I deal with cold callers like this...

    "Hello I am calling because your phone number has been selected to receive a free mobile phone..."

    Don't you just love these people?

    Well I do. In fact in a perverse way I almost welcome their calls. The reason is fairly simple but first a little background on telesales and how it works.

    Company X wants to sell its latest nanowidget and so it hires some dodgy telemarketing firm to ring hapless people who are foolish enough to have telephones in the hope that they will buy some nanowidgets. The way (as I understand it) the money is made is the person making the call will be on commission so it's in their interest to either get a sale or turn a dead-end call around ASAP so they can get onto the next one which might turn out to be a sale. Usually a computer makes the call rather than the person then when the call is answered the computer routes the call to the next available operator which is why you sometimes get those silent calls when an operator isn't available or the computer misfired. When an item is sold the telemarketing company get s a cut out of which it pays the operator who made the sale, ther phone bill and pockets the rest as profit with the remainder being passed to company X as a sale.

    So it's all about a shotgun approach - call as many numbers as you can. Terminate dead-end calls as quickly as possible and plough through as many as you can because the percentages say you'll get a hit in every hundred calls or whatever. If they can't get those calls out of the way fast enough they're directly losing money (they still have to pay an operator something and pay the phone bill for the call and they will have given expected figures to company X for sales which they're under pressure to meet).

    Now, this is why I actually like getting telemarketing calls...

    Whenever someone calls to try and get me to buy something I say "Oh, hello, how are you" and they say some greeting stuff and begin their opening script. "Hold on a second," I say, "you really need to talk to my (brother/sister/wife/mother/grandfather/cat/milkman) about this as they always deal with this. Just hold on a moment, I'll get them for you".

    You're now at the most important point of the call - the point where you put the phone down (DO NOT hang up, just lay the handset down on the table with them waiting. From this point on you are losing the operator commission, losing the telemarketing company potential revenue and running up their phone bill.

    "How do I know when to hang up?" you may ask, and a very fair question it is, too. You know when to hang when phone makes this noise:


    If everyone treated telemarketing calls like this then pretty soon no-one would ever have to worry about receiving one as there'd be no telemarketing companies left.

    1. Anonymous Coward
      Anonymous Coward

      Re: Alternatively

      That cuts down on a lot of calls and letters, but not all. I still get phone calls from other countries, including English operators claiming to be in the Netherlands, saying they're not subject to such rules and cannot remove me from their list.

      If you're going to pay someone for this kind of service from BT, my instinct is to avoid them and go to an independent company who can almost certainly be relied on more to get it right.

      Like the mighty Sony Corporation and Playstation customer personal details. Or Findus 'beef' burgers.

      1. Alan Brown Silver badge

        Re: Alternatively

        The callers may be from other countries, but you can still go after the companies they're acting on behalf of, assuming those have a british presence.

    2. Lusty Silver badge

      Re: Alternatively

      TPS doesn't work at all. All of my numbers are on there but I have now unplugged the house phone due to the number of calls. You may not think you get many, but try working from home throughout the day and you'll soon realise what a pain these calls can be.

      I can only assume that BT must have a department dedicated to sorting this because it will eventually lead to people not bothering with landline calling at all.

    3. frank ly Silver badge

      @ge Re: Alternatively

      Why not go all the way, tell them you're interested in buying a nanowidget and get them to send a salespup round to give a demonstration in the comfort of your own home? Imagine the fun you could have 'testing' the nanowidget and pointing out all the flaws it has.

      Then you offer perform consultancy services to improve the design of their nanowidget and ask for a working lunch with their managing director. You also send them an invoice for the 'initial consultation' with the salespup. The possibilities are endless.

      1. JeevesMkII

        Re: @ge Alternatively

        Generally they're not even sales calls, they're just straight up scams.

        We get calls, sometimes twice a day, from the "Microsoft support department" offering to fix problems with our computers. I always presume since they're willing to peddle one form of scam, then any sucker who actually pays them gets a trojan for their trouble.

        Having a land line these days is vastly more trouble than it's worth. If you're moving to a new place, just chuck that fixed line phone in the bin and if you must have a communal house phone, make it a prepaid mobile.

        1. P. Lee Silver badge

          Re: @ge Alternatively

          Haha! I had the "MS support dept" on the phone for over 40 minutes going round and around in circles with various supervisors and so on, trying to work out where the "windows" key was on my mac.

          Eventually after much swearing at me (and attempts to get my daughter's names so they could make obscene remarks about them too) they hung up on me.

          I take the view that as long as they are talking to me, someone else isn't being scammed.

          It was a slow day... but a good day.

    4. I like noodles

      Re: Alternatively

      @g e

      If I have the time and inclination, I try to "sell" something back to them.

      e.g. "Hello, yes I'm the householder. It's snowy here, is there snow there too? Oh right, there is snow? Is it cold? Yes? It's not cold here at all, I'm using a new type of insulation. I can do you a quote for insulation, I supply and fit and I've an exclusive deal with the Norwegian distributor for the UK here. If you just give me the building address there I can send round a team of engineers to assess your requirements. Sorry? You can't talk to me about your insulation requirements? Ah, so you're not a budget-holder. Ok, put your manager on, I'll talk to them."

      etc etc.

      Suprirising how far you can take some of them before the final point of victory, which is of course getting them to hang up on you

    5. Pie

      Re: Alternatively

      There is another way of dealing like this especially for particularly irritating frequent callers.

      Say oh you need to ring back on another number and talk to 'Mr X' the number is 0871 xxxxxxxxx

      If you are a company with a phone system it isn't difficult to get a free 0871 number with you taking a share of the calls, then have that set to an answer phone for 'Mr X' and your frequent nuisance calls are reduced at no cost to your business (you could probably do this privately as well)

    6. Valeyard

      Re: Alternatively

      my mum has been getting calls from a manchester number and when she hung up they started ringing her from mobiles and actually threatening with sexual violence. She's had to get the police involved a few times.

      If you annoy these people even slightly don't think for one minute they're above taking it very personally, just a warning

  4. Tom 260

    Useless really

    Calls from behind NHS switchboards are given as 'withheld', and due to data protection, these callers often won't leave any useful information on answerphones.

    1. Paul Shirley

      Re: Useless really

      BT also strip CLI off incoming SIP calls, showing them as international. Anticompetitive to the core. They'd rather harm competitors than help their customers. So no surprise this is such a blunt and useless tool.

      1. Steve Evans

        Re: Useless really

        I believe the reason BT strip the CLI from SIP originated calls is because such SIP CLI is generally about as trustworthy as two dozen politicians holding expenses forms.

        I have yet to have such a stripped CLI call ring on my home phone which isn't exactly what I expect - namely yet another company ignoring TPS.

        BTW, personal favourite is "Microsoft" calling because my computer has reported a fault to them. These calls seem to go through phases, and me and several friends have a competition going to see how long we can string them along for. Unfortunately I'm not currently winning (I had to cut the call short at 35 minutes, I was on the way out the door at the time). So please *do* call back. Your call is important to me (I need to beat Dave's 50 minute epic!).

        1. Paul Shirley

          Re: Useless really

          @Steve Evans: you may not receive legitimate VOIP calls, I do, my family get them a lot from me.

          When BT strip CLI they remove an important clue about each call, the chance of some scammer picking a faked number I recognise *and will answer* is close to zero. While legitimate calls can be recognised I can feel safer ignoring everything else, withheld or not. While legitimate calls are deliberately commingled with spam I can't simply ignore everything.

          Strangely VirginMedia and all the mobile networks seem to agree, it's just BT making life difficult for competitors.

      2. Nigel Whitfield.

        Re: Useless really

        @Paul Shirley

        They don't strip it off every SIP call; my calls from home go via a Gamma Telecom SIP trunk, and people I ring on BT lines do get my caller ID; I'm pretty sure they also get the ID when I ring via the backup SipGate account too.

        So it's not a blanket thing stripping at all.

    2. Dave 126 Silver badge

      Re: Useless really

      >Calls from behind NHS switchboards are given as 'withheld', and due to data protection, these callers often won't leave any useful information on answerphones.

      It is my understanding that public services have to ring you back on a non-withheld number. My friend has paid BT a quid a month for years to block all unknown numbers to his landline. I asked him about doctors etc, and he said they were required to call him from an identifiable number.

      I answered an 'unknown number' the other Saturday evening on my mobile, turned out to be a mate requiring a lift home from a police station in the next city (after being released without charge)- his mobile had no credit since he had neglected to pick up his cash card when they arrested him from his house. He had tried his brother and his closer mates, but not one had picked up his call - no doubt expecting it to be a sales call.

  5. Anonymous Coward
    Anonymous Coward

    Shoddy builders

    They're like shoddy builders who come to lay your new patio, then three months later when you complain that all the paving has come loose, they say they'll fix it for an additional fee.

    Do someone a favour, wring Busby's neck.

    1. Busby

      Re: Shoddy builders

      What did I do?

  6. Andrew_b65

    TPS is wank

    The TPS is able to act only on unsolicited LIVE 1to1 calls. Pre-recorded messages are not covered by the scope of the TPS which is why it is completely crap and useless. Have you noticed how most of these unsolicited calls start with a recorded announcement with a list of options to speak to an operator?

    The TPS is perfectly fine with this activity. Their remit needs to be changed to encompass recorded messages.

  7. Anonymous Coward
    Anonymous Coward

    The biggest spam caller and texter on my my mobile (vodafone) is vodafone

  8. Graham 25

    Wouldn't it be simpler ?

    To just have BT and other UK carriers, block any calls coming from overseas which do not have full CLI attached so at least the recipient knows its a call from overseas and treat it accordingly.

    That way, the majority of calls from India for example, can be immediately spotted by the recipient and safely ignored. If the caller then buys a block of UK numbers to use, they pay out up front and then lose them if they spam thereby costing them a small fortune.

    My current bane is from the 0843 410 XXXX lot who are working each of those 9,999 CLI's to make automated calls.

    1. Colin Miller

      Re: Wouldn't it be simpler ?

      My caller display phone will indicate if a withheld number is UK and international withheld.

    2. Martin Gregorie Silver badge

      Re: Wouldn't it be simpler ?

      "To just have BT and other UK carriers, block any calls coming from overseas which do not have full CLI attached so at least the recipient knows its a call from overseas and treat it accordingly."

      A much better idea would be for BT to block all calls from a number on the TPS list or from overseas and which are either silent and/or have the "withhold caller ID" flag set. The caller should be charged a premium for the privilege of being blocked. This would stop the nuisance calls and keep BT happy because it would be getting paid for doing the blocking. As others have said, this would work because BT always knows the actual caller - without that information it doesn't get paid for the call.

      1. Anonymous Coward
        Anonymous Coward

        Re: Wouldn't it be simpler ?

        Erm, How would you know if a call is silent until it's been answered?

        BT doesn't know the caller unless the call originated on a BT line - all it knows otherwise is the operator who is passing them the call and the originator's number in the signalling information. Payment works on 'next in chain' in telecoms - whichever operator passes the call to me pays me, I keep a bit for my trouble and then pay the next operator in the chain.

        The rate paid is set by call type - so an operator might get 0.1p a minute for a UK geographic number call. There's no mechanism to charge extra depending on whether or not CLI is witheld and how would you bill it? They don't know the operator who generated the call, just the one who passed it to them.

    3. We're all in it together
      Thumb Up

      Re: Wouldn't it be simpler ?

      Most of BT's tech support is in India so they block their own staff. Mind you maybe that's a good thing....

  9. Dogsauce

    If you ever get a human speaking to you on one of these calls, I find the following phrase useful:

    "Hang on a minute, let me interupt. Let me say something. You know those people at school who said you'd never amount to anything? They were right, weren't they?"

    Spammers of all hues are life-theiving vermin.

    1. Anonymous Coward
      Anonymous Coward

      Whilst satisfying its also hazardous they have your phone number, insulting will only result on your number finding its way onto every database imaginable. just buy a trucall and forget about it.

    2. cinsekrap

      And when your son/daughter is at University and has a job to pay the bills, etc.. in a call centre - you'll agree, right?

      There's no need to be offensive to the workers themselves. This kind of behaviour spreads beyond the call centre call from abroad and suddenly it's acceptable to make personal insults to someone we've never met, who is - at least - working.

      1. diodesign (Written by Reg staff) Silver badge

        "suddenly it's acceptable to make personal insults to someone we've never met"

        Ah, you've seen the contents of my inbox, then?


    3. Nuke

      @ Dogsauce

      Wrote :- "I find the following phrase useful: "Hang on a minute, let me interupt. Let me say something. .."

      Don't interrupt them. The longer their call goes on the more it costs them in time and money. Better to put the handset down without hanging up and return to it 5, 10 or 15 minutes later, whenever they have given up.

      Alternatively, if you want some fun, let them finish their spiel, and then in a heavy accent say "My Eeenleesh not good. Please say all again, ve-ery slow pleeez ..."

      Or wait until they have finished and say "We are very interested, but you need to speak to a Mr Jones here - please wait while I fetch him to the phone". Then leave it.

  10. YP

    the new bane of my life

    is the message that says 'this is an important message about <blah> press 1 to call us back, or 9 to be removed from the database'

    How on earth can I stop these? I really don't believe pressing 9 does anything other than let them know I picked up.

    And while I'm at it, it's the people who say 'this is not a sales call, we are conducting a short survey....'. At least I have fun with the 'I am John from Windows Support, you have problem with your computer we can help' Not had them fora log time unfortunately.

    1. Anonymous Coward
      Anonymous Coward

      Re: the new bane of my life

      Think they can probably detect that you picked up whether or not you pressed 9.

      In reality I suspect that this automated response is just a method of allowing them to do automated dialing and not have "silent calls" when more people pick up than they have people to answer.


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