How to Stop Nuisance and Scam Phone Calls

preventing scam phone calls

preventing scam phone calls

Have you received a missed call on your phone starting with +231 (Liberia)? Or perhaps +269 (Comoros), +216 (Tunisia) or +682 (Cook Islands)?

Ring that number back and you get a you’ll get a nasty surprise on your phone bill. We’ve put together a guide to help you avoid these and other unwanted calls.

There’s been a lot of coverage in the press recently of scam calls from abroad which lead to expensive callback charges, and everyone has had time wasted with nuisance calls at some point. If you’re a business going ex-directory will never suit, in fact you need your numbers published everywhere so it’s easy for anyone to ‘scrape’ them. Let’s take a look at this guide to practical techniques which can be used to filter these annoying phone calls. (Aside: we can also use the same techniques to improve customer service!).

Identifying the types of calls we want to block ?

There are different types of nuisance calls, so let’s try to categorise them;

  1. Automated Surveys.  These calls will use auto-dialers to connect to your phone, then pass you to an interactive voice response (IVR) system to gather information. Sure you can hang up, but it’s annoying.
  2. Scam Dial Back Fraud. These calls will ring long enough to leave a caller-id on your phone (at no cost to the caller) which you then call back at great expense. The scammer will collect revenue share on the inbound calls. Typically these calls are initiated from abroad but it’s often easy to hit the ‘call back’ function on your phone without noticing the number.
  3. Persistent Pesterers.  These are the cold calling companies that have you on a list. They call you once a week to inquire about your energy bills etc.. Well now you can put them on a list, so they don’t bother you again.
  4. Risky International.  Some can be scams trying to get you to install malware on your PC, some can be telemarketing low cost development or support services. Either way, we’d rather avoid them.
  5. Anonymous Callers.  Everyone uses caller-id these days. If it’s missing,there’s a strong possibility somethings fishy ..( and might also like to get a phone number for leads ). We can handle these calls gracefully.

Primary Techniques for Filtering Calls

Now that we’ve identified the types of calls, we can look at how to stop them in their tracks. There are two main methods we will use.

  1. Prompt and Collect. We will answer the call and prompt the caller for information. Of course this can be useful for streaming and improving the customer experience (useful call stats too) but in this case it serves two purposes; Firstly any automated surveys can’t make a selection, so they are stopped in their tracks and secondly many persistent pesterers will be put off as they are on a schedule. Additionally scam dialback fraudsters will never reach the end phone.
  2. Caller-id Screening. We will use the caller-id presented and match it against number lists and patterns to determine the call routing. Using this method we can screen persistent pesterers, anonymous callers and risky international. 

A Practical Example.

screen nuisance calls

In this example when the phone number +35351123456 is called, it’s routed to a menu and the caller is prompted to ‘press 1 to continue’.

Next we check if the call is anonymous, if it is, we playback a message ‘Sorry, we don’t accept anonymous calls, please activate your caller-id, then call us back’.

Next we check against a so called ‘Black List’ of numbers and/or patterns which are NOT allowed. For example is we have a persistent pesterer we place them on this list. If you’re on the list you hear a polite message, then we hangup.

Next  we check against a so called ‘White List’ of numbers and/or patterns which are allowed. For example we could put a pattern for matching all Irish numbers on this list. If you’re NOT on the list you hear a polite message, then we hangup.

Finally all the wanted calls end up on ‘My Mobile’


Improving Customer Service

Of course you can use the same techniques to improve customer service. Here we add an additional call screening to separate calls originating from specific cities (based on caller-id patterns).

filter caller-id by region

In summary scam and nuisance phone calls are annoying but can be dealt with simply and efficiently. However, when we take some time to examine how  our inbound calls are managed, we can also perceive other improvements which benefit the business.


LazyPBX logoThe above technique to managing scam and nuisance calls can be applied to many phone solutions.The above screenshots are from CallBrix where the setup takes just a few minutes.  We provide you with lot’s of other cool tools like; number tracking, call routing, phone recording etc.. to manage your calls professionally. Take a free trial. 

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