Complaints about "junk mail" appeared to have increased during the 1960s and started to be taken seriously at around 1970. We have already met James Dickens MP (Labour), who talked about how advertisers were using the electoral register as a junk mail list. His main concern was that these advertisers were targeting young adults with literature on sexual matters. Dickens' disdain of unsolicited mail was shared by many of his colleagues in the Labour Party. In 1972, for instance, the party resolved to introduce an advertising tax (which never happened) and two years later the Minister for Prices and Consumer Protection told the Advertising Association conference in no uncertain terms that it needed to get its house in order.

The Labour Party's disapproval of advertising gave a boost to self-regulation within the industry. That was mainly done by strengthening industry codes of practice but it also led to the first official opt-out scheme for junk mail: the Mailing Preference Service (MPS). The scheme was first announced by Lord Redesdale (5th Baron Redesdale) on 10 February 1983, in a House of Lords debate about the Data Protection Bill:

"I should like to crave your Lordships' indulgence for a few brief moments. I have to declare an interest in that I am the president of the British Direct Marketing Association, which covers all forms of direct marketing, including direct mail. The industry is shortly to launch a scheme, the Mailing Preference Scheme, which allows members of the public to have their names withdrawn from mailing lists by writing to a central organisation. I think that this will be of great benefit to the public."

The Lord went on to say he was worried the new scheme could be put into jeopardy by list brokers ignoring the new opt-out scheme. He also put forward an amendment that would crack down on such companies. In effect, all list brokers would be required to check their mailing lists against the MPS. The amendment was promptly rejected and so the MPS remained a non-statutory, voluntary industry opt-out scheme that only covers addressed junk mail distributed by members of the Direct Marketing Association (nowadays known as the Data & Marketing Association).

Boosting registrations

In the first few years of its existing the MPS did very little to encourage people to sign up and awareness of the opt-out scheme was low. To the best of my knowledge there are no figures but an old clip from Thames News, dated 4 November 1987, shows that they had only just started to give Citizens Advice Bureaus and libraries leaflets with information about the scheme. The news items includes a brief interview with the above-mentioned Lord Redesdale.

The MPS's obscurity was also raised in the House of Lords, in June 1990. Lord Campbell of Croy (Conservative) asked if the government would encourage and publicise arrangements made to enable citizens to have their names and addresses removed from lists used for sending unsolicited and unwanted mail. The Government's reply was that its friends within the industry were planning another campaign":

My Lords, the Government recognise the value of the Mailing Preference Service and alert individuals who complain about unsolicited mail to its existence. Advertising and promoting this scheme to consumers is a matter for the industry and I understand that it has plans for an additional promotion.

Going online

It would be unfair to say that the MPS only started to advertise its existence in 1987. The leaflet shown here dates from 1984, so that proves the DMA made at least a half-hearted attempt to make people aware of the opt-out service. Still, things only really improved when the MPS website was launched in 2001 (the website was first discovered by the Wayback Machine in November 2001).

The very fact that the website was created is noteworthy, as the industry has since been rather reluctant to let people opt out online — to register with opt-out schemes for unaddressed mail you still need to print and return paper opt-out forms. On the other hand, the Telephone Preference Service (TPS) website had been launched the previous year, so it made sense to also have a website for the MPS. Plus, junk mail volumes boomed in the early noughties. Advertising mail was deeply unpopular, and with Labour in power the industry had to again demonstrate that it could regulate itself.

The original MPS website featured three separate opt-out forms. MPS Registration Form A let you register your surname at your address. This meant that anyone in your household with the same surname would be opted out. Of course, that meant that some junk mail lovers in a household could be opted out by accident. For that scenario there was MPS Registration Form C — the form was used to opt in an individual at an address. The form included a list of areas of particular interest as well, so you could opt in to receiving specific types of adverts. Registration Form B was used to register the name and address of someone who had died.

Since 2007 the Mailing Preference Service is purely an opt-out service for individuals. You can no longer register an entirely household by just providing a surname, and junk mail addicts no longer have to explicitly opt in.

Opt-out numbers

The launch of the website led to a spike in registrations and finally made the MPS something of a household name. In 2003, 1.5 million households were register with the MPS. By 2006 the number had more than doubled, to 3.3 million. From 2007 onwards the picture is less clear, because of the above-mentioned switch to individual registrations. As at March 2025 there are 3.5 million records in the "household file" and 3.3 millions records in the "personal file"). However, it would be wrong to conclude that the MPS therefore has 6.8 million subscriptions. The household file hasn't been updated since 2007 and has little value — each record is at least 18 years old and therefore unlikely to be current. That isn't a bad thing — it is still useful to suppress the surnames of people at an address who have since moved house or died — but it is of little value if you want to estimate the number of active registrations.

And, speaking of stale data, another complication is that registrations no longer expire. Until April 2012, registrations with the MPS were valid for five years. Every month, the MPS would remove registrations that had expired from the personal file, which obviously reduces the number of registrants. Since 2012, registrations lasts forever. That is a sensible policy but it does mean the data on the file becomes increasingly stale over time. The suppression file includes lots of people who have since moved house or passed away.

In short, the number of people who are registered with the MPS at their current address will be 3.3 million minus any stale records. The exact number is unknown but it is fairly safe to assume that it is somewhere between two and three million. That works out at roughly five per cent of the adult population.

Up to 95% effective?

For many years the MPS website claimed that opting out would stop up to 95% of all direct mail. The claim was highly misleading. For starters, only members of the DMA are obliged to check if people on their mailing list are registered with the MPS. Whereas there is a legal requirement for telemarketers to check if phone numbers have been registered with the TPS there is no such requirement for junkmarketers. As the 5th Baron Redesdale pointed out in 1983, the MPS is a voluntary, laissez-faire industry scheme. There are lots of companies and charities that don't check if people have registered with the MPS.

In addition, the opt-out scheme is rather lenient when it comes to matching names. As mentioned, the MPS initially registered a surname at an address. That changed in 2007; you now register as an individual at an address. That creates an interesting problem: what should a junk mailer do if a name doesn't match exactly? For instance, let's say your name is "John Smith" and that a junk mailer has the name "J Smith" on its list. Should they assume "John Smith" and "J Smith" are the same person? The answer is that this is up to the discretion of the junk mailer.

And, of course, the MPS also doesn't stop junk mailers who tricked you into signing up to receiving adverts. Strictly speaking, such mailings are solicited, even though recipients might not realise they asked to be added to a junk mail list.

In short, the MPS' claim about its effectiveness was a lie. I had raised that point with the DMA but they did what they do best: ignore any awkward questions. However, I did get them to remove the claim from the MPS website. In 2011, the remit of the Advertising Standards Authority was extended to include online advertising, including marketing messages on websites. They agreed the DMA was unable to substantiate its claim and the DMA duly removed it from the MPS website. This is important, as it stops lazy journalists and MPs repeating false information about the effectiveness of the service.

The "To the Occupier" loophole

From the outset, the MPS has made an exception for mailings addressed to generic addressees, such as "The Occupier", "The Householder" and "The Mistress of the House". Even in the olden days, when the scheme worked on a household level, you would not be spared such mailings. In effect, this creates a loophole. Junk mailers who don't want to pay £1,540 plus VAT for the MPS suppression file can simply send their mail-outs addressed to a generic addressee. It is cheap; they don't have to check their mailing list against the MPS and they don't have to worry about complaints (as recipients have no-one to complain to). Companies like Virgin Media used to adopt this approach; for many years they bombarded the country with "The Householder" junk mail. At some point they set up their own opt-out scheme, as there were so many complaints about their relentless junk mail campaigns.

I of course asked the DMA why the loophole exists, and they of course didn't answer. My guess it that they would argue that the MPS is for named individuals only. Still, it kind of makes sense for the junk mail industry to not target "To the Occupier" junk mail at addresses where at least one person is registered with the opt-out scheme. It is very unlikely the advert would be welcome. Perhaps the junk mail lobby feels they have no way of knowing whether or not there are any junk mail addicts at an address, but that would be an insanely principled stance. It would mean they deliberately create a loophole and undermine the effectiveness of their own opt-out service, purely to prevent other people at an address might be deprived from these mailings.

Governance

There is a wider point here. The MPS has always been an industry-run opt-out scheme without any external oversight. As is typically the case with self-regulation, the fox is guarding the hen house. And yes, the DMA has commissioned research that shows people registered with the MPS reckon the MPS does an excellent job but is of course exactly what a satisfaction survey amongst chickens would show if it was organised by a fox.

I am not saying the MPS is bad. It isn't. However, the service could be better. The MPS doesn't for instance publish any information about complaints it deals with. Even basic details, such as the number of complaints and the percentage of upheld complaints are unknown. Similarly, there has never been any discussion about whether or not it is really necessary for an MPS registration to become only fully effective after four months. There is some logic behind the four-month wait, as junk mailers typically screen their mailing list against the MPS suppression file at the start of a campaign. However, that is a choice. It is entirely possible to do another quick clean-up before handing over junk mail letters to Royal Mail for delivery. It would make the MPS more efficient and could be a requirement in the DMA's Code of Practice.

Similarly, the MPS has an informal approach to third-party registrations. In the noughties some councils were actively encouraging people to reduce junk mail. Many offered free "No Junk Mail" signs, and some actively collected the names addresses of people wanting to register with the MPS. Those lists were accepted. However, when I launched a website called Junk Buster, which let people contact up to six different opt-out schemes for different types of junk mail via a single form, I was quickly told that third-party registration weren't allowed. That was obviously false but there was nothing I could do. The MPS doesn't have any written rules. Instead, they simply make up the rules as they go along.

In short, there is a strong argument for more transparency and oversight. The Fundraising Preference Service, which is the most recent industry-run junk marketing opt-out service, could serve as a blueprint. Anyone interested in the service can find a wealth of information on its website, including annual reports; information about how the service is governed and how many complaints have been received and dealt with. There is no reason why the MPS couldn't do something similar.