When customers buy or hire goods from you they have certain key legal rights.
Requirements for goods
The goods must match the description you give of them. If you say a computer has an 500Gb hard drive it can't be 250Gb. You don't have to say a country cottage is in a quiet location but if you do it can't be next to a busy lorry route. For more information, see fair trading, trade descriptions and Trading Standards.
The goods must be of satisfactory quality - which means they must be of a standard that any 'reasonable person' would regard as satisfactory. They should be safe, work properly, and have no defects in their appearance or finish.
The goods must be fit for the purpose specified - meaning they should be capable of doing what they're meant for. A watch should tell the time - and if the customer said they wanted to use it while swimming and you didn't say it was unsuitable, it should be able to perform this task.
Who is responsible?
In law, the customer has these rights against the supplier of these goods. That means your business, if you have sold them, rather than the manufacturer.
In some cases, the goods may be covered by a manufacturer's guarantee, meaning the manufacturer will repair an item free of charge. But this doesn't affect a customer's rights against you as a supplier. For more information, see returns and refunds, warranties and complaints.
Consumer vs business customers
In addition to these rules, if your customers are consumers they are also protected from unfair treatment by traders. You must not use unfair commercial practices that are misleading or aggressive or omit or hide key information that a consumer might need to make a free and informed purchasing decision.
If your customer is a business or acting on behalf of a business, they are protected by rules that prohibit misleading advertising.