Your marketing and advertising activities are one of the primary ways in which customers interact with your business. Marketing your business honestly is good for your reputation and helps you comply with legal requirements. The rules are stricter if you sell to individual consumers rather than to business customers, particularly if you're sending marketing emails.
Email marketing is regulated by the E-Commerce Regulations, which ban the sending of unsolicited marketing emails (also known as 'junk' email or 'spam') to individuals unless they have agreed that you can, known as 'opting in'. As well as covering consumers, this also applies to marketing emails you send to sole traders and individual partners in a partnership.
If your email marketing campaign is directly relevant to people's work, you can send unsolicited marketing emails to people at limited companies or limited liability partnerships. For example, if you're selling print services you can email the people responsible for stationery buying or marketing and promotion - even if you haven't got an existing relationship with them.
In any event, you must always provide a clear and easy 'opt-out' mechanism in all marketing emails you send, so that recipients can easily remove themselves from your list and stop receiving marketing emails from you. These rules apply even if you buy in an email list from a list broker.
You must ensure that your marketing activities comply with consumer protection regulations. These prohibit marketing techniques that would impair the average consumer's ability to make an informed decision.
Product labelling is covered by these rules, but note that special labelling rules apply to some types of product. You may want to check with your trade association or professional adviser.
Marketing through social media can be a legal mindfield - having a good internal policy for staff is vital.