One of the best options is to visit a sim card shop in London during the day. This is because the shops are usually busy and they will be able to provide you with a better service. Alternatively, you can also try looking for sim card deals online. There are many websites that offer sim card deals, and you can usually save a lot of money by using these websites. You may get a sim card from most convenience stores, such as Mobile Junction, which sells Public Mobile, Lucky Mobile, Freedom Mobile, and Chatr Mobile sim cards. Call us at (226) 582-5333 or come see us now.