Home currency: Just keep a small amount of money with you just in case you need to give a tip to the person helping you carry your bags from the airport or driving you back to your house when arriving home.
The keys to your house: Take the keys to your house so when you return home there won’t be a problem getting in.
Mobile phone: All the mobiles you usually use, and if you have a spare phone, it is recommended you bring it. It is cheaper to place an English SIM card in your spare phone while you are visiting London, than to use your local number to make calls.
Appliances and chargers: Take all the appliances you need (laptops, tablets, etc.) and their chargers. It is highly likely that UK plugs are different from what you are used to. So if you already have English adapters, then please bring them. Don’t worry if you don’t have any - you can find them in plenty of stores.
A pen: Keep a pen with you, as you will need to fill in a landing card when entering England.
Your clothes: Don't forget to take appropriate clothing with you depending on the weather forecasted. You can find everything here but it will take you some time to find seasonal clothing like swimsuits in the summer or coats in the winter.
Toiletries: hair brush, tooth brush, tooth paste, facial wash, facial and body cream, shampoo and conditioner, towels (if you are going to stay in an apartment and not a hotel).
Sanitary pads: Ladies - it is preferable to take sanitary items that you are used to with you, because you may not find the same brand or specific ones used in the UK.
Items for the kids: Bring everything that your kids are used to having on a normal day, to avoid issues or tears. Especially bring along any medication or formula they need if still at that young age where everything matters! Keep an umbrella with you just in case it rains. We recommend you keep it with you all the time if coming to London during the winter. Always make sure you check the weather forecast before travelling.
Mark your bag: To be sure that you don’t lose your suitcase, you should mark your bag or tie a coloured scarf around it. This will prevent it from getting mixed up with someone else’s bag. Also, make sure you write your contact information on your bag just to be sure it comes back to you in case it gets mixed up.