The potential offenders

Let's first quickly mention the three sources of unaddressed junk mail:

Royal Mail

Unaddressed adverts delivered by your postie can be stopped by registering with Royal Mail's opt-out scheme for leaflets: the infamous Door-to-Door Opt-Out.

Members of the Direct Marketing Association

Unaddressed items distributed by DMA-members can, in theory, be stopped by registering with the Your Choice Dummy Scheme.

Other companies / individuals

Items delivered by local distribution companies or by individuals aren't covered by either opt-out scheme. You can deter the deliverers with an anti-junk mail sign.

What is unaddressed junk mail, anyway?

The two opt-out schemes will stop all unaddressed mail items, with two exceptions: if you're registered with Royal Mail's opt-out scheme you'll still get information leaflets from local or central government and so-called 'election communications' (that is, you'll get a single leaflet from every candidate in your constituency before a general election). Apart from that both the Royal Mail and the Direct Marketing Association make no distinction between unaddressed mail items that are commercial and non-commercial.

It's a shame the industry adopts such a simple definition of 'unaddressed mail'. When you think of 'junk mail' you probably think of leaflets from take-away outlets, estate agents, supermarkets and the like – that's the stuff you'd like to stop. But when you contact the Royal Mail or Direct Marketing Association to opt-out you'll suddenly get warnings like these thrown at you:

By taking this action, you may not receive local free newspapers or important items of information from the government, local authorities and utility companies.

And your signature needs to be placed under statements like these:

I am aware that by taking this action I may not receive important information from the government, local authorities and utility companies.

Both quotes come from the opt-out pack for the Your Choice scheme – Royal Mail uses less draconian warnings /scare tactics. These warnings are one of a number of reasons why the number of households registered with opt-out schemes for unaddressed mail is negligible (other reasons are that the schemes aren't very well advertised and that registering is complicated).

It would help people if the Royal Mail and Direct Marketing Association would make a distinction between commercial and non-commercial mail items. It's entirely possible. In the Netherlands, for instance, the junk mail industry's code for the distribution of unaddressed printed advertisements uses this definition of 'unaddressed advertising mail':

Any printed matter which consists wholly or partly of advertising, with the exception of free local newspapers.

Simple, isn't it? Only if a leaflet features one or more advertisements it's commercial junk mail. A leaflet about bin collections from the local council, however, would be non-commercial. And it gets even better – the Dutch code also defines 'free newspapers':

Unaddressed printed matter which is distributed door-to-door free of charge at regular intervals in a geographically limited area and of which at least 10% of the contents consists of information and news, but no advertising, about the area of distribution in question, and which in addition also contains advertising messages.

Ok, that's a bit of mouthful but you get the idea. Circulars featuring only sponsored articles and advertisements – and no genuine news about the local area – are considered commercial. When such items contain at least a small amount of journalistic articles (10%) it's a proper paper, and the item would be classed as non-commercial.

Sadly, the Direct Marketing Association in the UK treats all unaddressed mail items alike. Anyone can see that pizza leaflets, free newspapers and information leaflets about elections are quite different mail items. Yet, our national junk mail lobby group prefers to scare people into not registering with its opt-out 'service' for unaddressed mail.

Anti-junk mail signs

Although the junk mail industry doesn't in any way endorse anti-junk mail signs they're a vital tool in your battle against leaflets. The two opt-out schemes for unaddressed mail cover roughly half of all unaddressed junk mail. Even though 'No Junk Mail' signs are a purely informal way of stopping junk mail you need a sign if you want to really reduce the amount of leaflets you get.

Because there's no accepted definition of 'unaddressed mail' in the UK it's unclear what items a sign that reads 'No Junk Mail' should prevent. It should prevent take-away menus, for sure, but how about free newspapers? And what about a leaflet from your local council? They're unaddressed and unsolicited – but they're not commercial. If you're going to get a sign I'd recommend you buy one with the text 'No Commercial Leaflets' rather than 'No Junk Mail'. For many years I sold such stickers.