You may bring more than one item through security at Heathrow, and most airlines allow you one piece of hand luggage and one personal item --- like a purse or briefcase --- on board, but check for additional restrictions. Heathrow's website urges you to limit bags to 22 inches tall by 17.7 inches wide by 10 inches deep.
Heathrow allows travelers to carry on 3.4 ounces (100 milliliters) or less of liquids, gels, aerosols, or lotions. Keep them together in one transparent plastic bag, no larger than 8 inches by 8 inches, for separate security screening. Taste baby foods and liquid medications in front of security personnel to exempt those liquids from this rule.
Place all of your personal belongings in the X-ray machine at the security checkpoint. Remove laptops and electronics from bags, and put into separate trays. Remove coats, scarves and jackets, and place in trays. Place wheelchairs and baby strollers on the screening belt as well. Film with speeds of less than 1600 must be screened as well.
Leave needles, knives, tools, and razors at home. The only items of this kind allowed through security are scissors with rounded blades less than 1.2 inches long.
Heathrow security prohibits a variety of other items in your hand luggage: catapults, corkscrews, toy or replica guns, sporting bats, sporting cues, Christmas crackers, party poppers, multiple cigarette lighters (one is allowed, if screened as a liquid), non-safety matches and large, pointed golf umbrellas.
