Unaddressed junk mail is largely unregulated. Leaflets distributed via Royal Mail can be stopped by signing up to the company's Door-to-Door Opt-Out and leaflets distributed by members of the Direct Marketing Association are covered by the Your Choice Preference Scheme. All other leaflets – that is, the vast majority – are unregulated.

Leaflets from junk food chains such as Domino's Pizza, Papa John's and Pizza Hut are usually distributed via Royal Mail and can therefore be stopped (at least in theory). Local junk food outlets mostly distribute their own menus and together with estate agents these companies are renowned for ignoring 'No Junk Mail' signs.

Assuming that the leaflets come from local junk food companies there's very little you can do to stop them. Anti-junk mail stickers are a purely informal way of stopping junk mail – a polite request, if you like – and these companies operate outside the junk mail industry's self-regulatory framework (i.e. they're not members of the Direct Marketing Association). Basically, they can do as they please.

You could try sending the junk mail offenders a trespass notice. This may work and could even earn you some money – but it does involve a fair amount of work. An easier approach is to return any leaflets you get in an unstamped envelope, with a note asking the company to respect 'No Junk Mail' signs in future. The offender will be asked to collect the item from a sorting office and pay the postage and a small admin fee – only to find their own leaflet. Once ignoring 'No Junk Mail' signs becomes a waste of time and money for sender they might become more considerate.