For reference:
What are the legal differences between selling online and traditional sales?
Online sales to individuals are covered by the Consumer Contracts (Information, Cancellation and Additional Charges) Regulations 2013 (which cover any form of Distance Selling, for example, sales made over the telephone). These require you to send written confirmation of any order to the customer (by mail or email) containing the necessary information (your name, description of the goods, and so on) and informing the consumer of their right to cancel the order.
What information do I need to provide to online customers?
When selling online to individual consumers you must provide full details of the offer before they purchase, and written confirmation (which can be sent by email) of the details before or with delivery (or during the supply of any service). Broadly speaking, the required information includes your details, a description of the goods (or services), delivery and payment arrangements, and information about the right to cancel. You also need to include information on the duration of any contract, the total cost including any deposits that may be payable and the customer's responsibility for the cost of any returns.
Can customers cancel online orders?
Individual consumers have the right to cancel purchases within a specified time under. This is 14 calendar days from the delivery date (for products) or from the contract date (for services) - a model cancellation form will need to be provided to customers. If you fail to provide the right information, the cancellation period is automatically extended to one year. Refunds must also be given within 14 calendar days.
That is just the start of the rules that you need to follow.
Go look up the relevant laws.
Note, some of the regulations may be out of date above, but they are all still relevant, though maybe slightly changed.
