When you buy something, consumer law says the item must be fit for purpose.
For example, a toaster must be able to make toast and a washing machine must be able to wash clothes.
As well as being fit for their normal purpose goods must also be fit for any specific purpose that the seller told you they would be fit for.
The law which gives you this right is called the Sale of Goods Act 1979.
This right only applies when you buy something from a business, not from a private seller.
What's the purpose of the goods?
In most cases it will be obvious what the purpose of the goods is. If goods aren't able to carry out their normal functions for any reason, they are not fit for purpose. The Sale of Goods Act 1979 says that goods that are not fit for their normal purpose are not of satisfactory quality and you may have the right to return them to the seller and get a refund.
The Sale of Goods Act also says that goods must also be fit for any specific purpose that you have agreed with the seller. For example, you might need a printer which is compatible with your computer. If you buy a printer because the salesperson says it's compatible with your computer, it must be compatible. If you later find out that it isn't, you can claim the printer isn't fit for purpose.
When you're buying something you need for a specific purpose, you should make it clear to the salesperson that you're relying on their expert advice. You should find out their name in case the advice turns out to be wrong and you want to return the item.
If you haven't told a salesperson that you need something for a specific purpose, you won't have a right to return it if the item turns out to be wrong. It must, however, still be suitable for its normal purpose.
For example, you need paint that's suitable for both woodwork and walls. If you haven't asked for this and find the paint is only suitable for woodwork, you can't claim a refund – unless the salesperson told you the paint was suitable for walls as well.
In some cases it may not be reasonable for you to rely on the advice of a salesperson. For example, if you buy a tin of paint in a general supermarket rather than in a specialist hardware store, it may not be reasonable to rely completely on a checkout person's opinion about whether the paint was suitable for a particular job.
What can you do if goods aren't fit for purpose?
If goods aren't fit for their normal purpose they aren't of satisfactory quality and you may have the right to return them to the seller and ask for a refund.
If something isn't fit to be used for a specific purpose agreed with the seller you may have the right to return it to the seller and claim a refund.
If you return the goods within a very short time of buying them you don't normally have to accept a repair or replacement instead of a refund, unless you want to.
If you've kept the goods for a while the law says you may have accepted the goods and have lost your right to a full refund. However, you should still have the right to get a repair or replacement.