Report Nuisance and Scam Calls

We're all on the same side

Whether you’re a Gamma customer, industry partner or just a concerned member of public with no links to the telecoms industry, we all need to work together to tackle the threats posed by nuisance calls and use of telecoms services by scammers.

This sort of activity causes real harm to all kinds of people and risks doing irreparable damage to the public’s view of the telecommunications industry by eroding their trust in the calls they receive.

Gamma is committed to tackling the problem of nuisance calls and scams with our partners and working with Ofcom and the wider industry. Please choose one of these options to see specific guidance and advice on how to tackle different kinds of calls.

Woman sitting at laptop

Types of nuisance calls

Marketing and sales

Marketing and sales calls – someone trying to sell you something

Most of these come from legitimate businesses if you don’t uncheck the “contact me with offers” or “share my details with third parties” boxes.


If you’re receiving unsolicited phone calls, you should register with the Telephone Preference Service (TPS).

The TPS is free to use and is a register which records your preference not to receive unsolicited sales or marketing calls.

If you’ve registered with the TPS and still receive unwanted calls, you can make a complaint to the TPS and it will investigate.

You can also report unwanted sales calls directly to the Information Commissioner’s Office (ICO) here. The ICO works closely with TPS, Ofcom and Action Fraud to combat unwanted calls.

Learn more about TPS

Scam calls

Scams – made by fraudsters claiming to be someone else

Scammers will normally try to get you to send them money (pretending you have an overdue tax bill for example) or trying to get personal information from you which will allow them to trick banks into transferring money directly.

The caller may sound urgent or threatening. They my ask for remote access to your computer. They may ask for passwords, bank details or other personal details.

The scam may be a text message, such as “You have a approved a payment of £264.34 to XYZ, if this wasn’t you call us on [number]”, or suggest you click on a link.

What is 159?
159 is an initiative from Stop Scams UK, a collaboration of businesses across the banking, telecoms and technology sectors, including Gamma. Find out more here.


If you think someone is trying to trick you into handing over money or personal details: Stop, Hang Up, Call 159.

If they claim to be from a respected business, look the business’s number up and call back. Don’t call the number from your call list or the number given in a text.

Report the number to the range holder. If it’s a Gamma number use the form below.

Report a scam call

Scam text messages

Scams – made by fraudsters claiming to be someone else

Scammers will try to get you to click a link in the message (by pretending your bank account is locked, for example) to get you to hand over personal details, or login credentials to your bank or email.

It’s important to be cautious if you receive a text message about a parcel you may be expecting, or your bank about a payment or transfer.


You can report a suspicious text message by forwarding it to 7726.

7726 is an easy, free service to report potentially fraudulent text messages. If you forward a message to 7726, your provider can investigate the origin of the text and arrange to block or ban the sender if it is found to be malicious.

How to report to 7726

Malicious calls

Malicious calls – calls that aim to distress you

Malicious calls may be abusive, threatening, or obscene. They may even be excessively regular, making your phone unusable and, if you are operating a business, preventing you from continuing your work.


You should report these calls to the police. It will help if you note down the date, time and number that called, along with any other information. Don’t engage with the caller.

Report a malicious call

Silent calls

Silent calls – when there’s nobody on the line

The phone rings, you rush to answer but there’s no-one on the line. A lot of silent calls come from automatic dialling equipment in call centres, where more calls are made than there are operators available to handle them.

Doing too much of this is a fundamental breach of regulation, and so Ofcom take a direct interest in it.


Report this directly to Ofcom. You can do so by visiting their website.

Visit Ofcom

I have received a call from Gamma

Why is Gamma calling me?

Gamma is almost definitely not calling you. We undertake no tele-marketing whatsoever, nor do we provide tele-marketing services to others. We are a wholesale telephone company, providing wholesale services to other phone companies, who in turn offer those to consumers and business.

Because we have so many phone numbers on our network, like any network, we sometimes find they are used for nuisance calls or fraudulent purposes.

But {Big Telephone Company/Online Forum} said Gamma was calling me.

Ofcom allocated phone numbers to networks, known as “range holders”. As a wholesale provider and range holder we have been allocated millions of phone numbers for use by our customers. Recipients of nuisance calls may quite rightly call their own telephone provider (BT, Sky, TalkTalk etc) whose customer service staff tell them to contact the range holder (“You need to complain to Gamma”) or even worse misinform the person that it was the range holder that was calling them (“The calls were made by Gamma”). If you use an online information tool or forum you will also be shown the range holder, not the end-user of the number.

Number spoofing

Number spoofing is all too easy to do with modern telecoms technologies while network standard and regulations are years behind on limiting it. If the caller ID has been spoofed, as is the case in most such calls we are unfortunately powerless to do anything.

It is analogous to someone sending you a letter via Royal Mail with FedEx’s address written as the sender – FedEx didn’t send it to you and has never handled that envelope but they’ll end up getting any replies. FedEx can’t stop you getting more even though it has their name on it. Royal Mail can as they are actually delivering the letter. Of course, if you reply to the FedEx address, it will go to FedEx just as if you ring one of the Gamma numbers it will come onto the Gamma network.

Report a Gamma number

I have a text/voicemail/email/website asking me to call a Gamma number

How would this look as a scam?

Scams like this normally pretend to be your bank, or someone like BT or Microsoft tech support. You can expect them to ask for personal details, to try sending some money to XYZ, or to give them remote access to your devices.

A lot of scams these days rely on encouraging you to call them rather than just calling you directly. If you have taken the initiative to call them you’re much more likely to trust they are who they say they are. People who decide to call have already missed the first opportunity to identify the scam.

On the other hand, in order to make a connection when calling someone, there’s no way to hide themselves and we can find their telecoms provider.

What can be done?

Unfortunately, most scammers operating like this buy temporary phone services using false details and stolen credit cards, so catching them isn’t easy. What we can do is ensure that the numbers involved are taken out of service to prevent future victims.

If you have been asked to call a number belonging to a Gamma range and you suspect a scam, report it to us ASAP so that we can take action.

Report a scam advertising a Gamma number

Someone has been using my number without permission

Number spoofing

The way this is done is through number spoofing (rather than somehow taking over your phone).

Number spoofing is all too easy to do with modern telecoms technologies while network standard and regulations are years behind on limiting it. Unfortunately, where caller ID has been spoofed, as is the case in most such calls we are unfortunately powerless to do anything.

When people are receiving calls that pretend to come from you, you can find yourself inundated with people returning missed calls and demanding to know why you called them.

How does it work?

It is analogous to someone sending a letter via Royal Mail with your address written as the sender – you didn’t send it and never handled that envelope, but you’ll end up getting any replies. You can’t stop them getting more even though it has your name on it. Royal Mail can as they are actually delivering the letter. Of course, if they reply to your address it will come to you, as with the returned calls.

What can be done?

If someone has reported the problem to you, for example by returning one of the calls, they need to understand that they have received a nuisance or scam call and should report it to their phone service provider who, like Royal Mail in the above analogy, will be able to see who sent them the call.

There are two likely scenarios:

  1. The caller is deliberately spoofing your numbers, likely to fool your customers
  2. The caller is just trying to obscure their identity

Scenario 2 is overwhelmingly more likely. Most of these callers are based overseas and are picking random UK numbers to appear more legitimate (people often won’t answer the phone to a withheld or international number). When this is the case, they will generally use a number for a few days and then move onto a new number. The problem therefore normally goes away fairly soon, but unless you can engage the call recipients as described above, the criminal will be able to continue and possibly scam more victims.

Is there really nothing else which we can do?

There are two more radical options, which are often not appropriate for business customers:

  1. If you do not use the number for outbound calls (e.g. it is purely an inbound service for your support team) Ofcom have a Do Not Originate list. UK providers are required to block any calls with numbers on that list. For information, and how to add your number to that list, visit the Ofcom website.
  2. You can change your number. For most businesses this isn’t possible because it will be printed on marketing materials and shared with customers, but if possible it will separate your business from the damage done by these calls. This may be an option if it is an individual’s direct number or an unadvertised number.

New Ofcom rules to fight number spoofing

Ofcom has issued new strengthened rules and guidance to phone companies to help them prevent scammers access to valid UK phone numbers – however these new rules are less stringent on UK mobile phone numbers (starting with 07 or +447) as there are many legitimate use cases for non-domestic origin calls from a domestic mobile number, including international roaming.

This may result in an uptick in scammers spoofing mobile numbers. You should exercise the same caution with a UK mobile number you don’t recognise as you would a landline, international or withheld number.

Read more about Ofcom’s changes here.

In the event that you believe your calls are being blocked in error as a result of these changes you should contact your service provider in the first instance. If we are your service provider please contact [email protected].

Report number spoofing

People have been calling me by dialling an unrelated number

How does this happen?

Call forwarding is a very simple thing to do, business phones allow it so you can divert to your mobile when out and about, network features can allow for lots of clever diversions, and even your own mobile will allow you to forward calls, for example when unreachable. Any number can be diverted to any other number, and normally the diverting party will pay for the onward call.

Why is it diverting me?

While it is possible that there has been a simple mistake, someone may have changes a 4 to a 5 when setting up their call forward and ended up with your number, far more likely it is part of a managed advertising service.

Companies like Yell, Hibu, Google and even Bing offer advertising or enriched directory services, and you are probably one of their customers. The way they monitor the effectiveness of their ads is to include one of their own numbers which then forwards calls on to you. They can capture statistics and show the value the advert is providing. Sometimes they will re-use old numbers (that someone may have saved), or numbers which are advertised elsewhere.

How do I stop this?

You will need to speak with your normal point of contact, or their customer support team. They should have no problem resolving the issue for you. Unfortunately, they do prefer not to engage indirectly (i.e. through Gamma) because of data privacy.

If you believe you do not have any marketing relationships, and the number people tell you they dialled is a Gamma number, then use the below form and we will do our best to find the cause of the problem.

Report call forwarding or diverting

Do you wish to report your experience to Gamma?

If you are receiving calls from a Gamma number matching any of the above types of nuisance calls, and you have reported the issue to the relevant body already, you can raise it with us using the form below.

We will investigate the issue to confirm whether it is a case of spoofing, for this reason it is important to include details of the calls received such as date and time, the caller’s number, and your own number.

If you can show that it is part of a pattern of calling (for example regular calls over a period of a week or more) or relating to a clear scam then we will pursue the investigation with our resale partners to put a stop to the issue.

Report a Gamma number

If you have not followed the expected reporting advice above we may not act on a report you submit.