American Express -- There are outlets at Heathrow Airport including at Terminal 4 (tel. 020/8897-0134) and at Terminal T3 (tel. 020/8759-6845). There is also an American Service Express Travel Service in London at 78 Brompton Rd., Knightsbridge, SW3 (tel. 020/761-7905). In Wales, the Amex office is at 3 Queen St. in Cardiff (tel. 02920/649305).

Area Codes -- The country code for England and Wales is 44. The area code for London is 020; Cardiff's area code is 029.

Business Hours -- With many, many exceptions, business hours are Monday to Friday 9am to 5pm. In general, stores are open Monday to Saturday 9am to 5:30pm. In country towns, there is usually an early closing day (often Wed or Thurs), when the shops close at 1pm.

Drinking Laws -- The legal drinking age is 18. Children 15 and younger aren't allowed in pubs, except in certain rooms, and then only when accompanied by a parent or guardian. Don't drink and drive. Penalties are stiff.

Breaking decades of tradition, England in 2005 abandoned its strict, often draconian, liquor laws, allowing 24-hour alcohol sales in England and Wales. Many pubs no longer close at 11pm, which used to be "last call." Of course, it's up to the publican, but many, if they elect to do so, could stay open day and night. It's not total nirvana for the pub owners, however. Some counties are stationing undercover officers in pubs to fine staff members who serve liquor to visibly drunk customers, and the problems of drunk drivers on the highway, policemen fear, will only increase.

Drugstores -- In Britain, they're called "chemists." Every police station in the country has a list of emergency chemists. Dial "0" (zero) and ask the operator for the local police, who will give you the name of one nearest you.

Electricity -- British electricity is 240 volts AC (50 cycles), roughly twice the voltage in North America, which is 115 to 120 volts AC (60 cycles). American plugs don't fit British wall outlets. Always bring suitable transformers and/or adapters -- if you plug an American appliance directly a European electrical outlet without a transformer, you'll destroy your appliance and possibly start a fire. Electronic equipment with motors intended to revolve at a fixed number of revolutions per minute probably won't work properly even with transformers.

Embassies & Consulates -- The U.S. Embassy is at 24 Grosvenor Sq., London, W1 (tel. 020/7499-9000; www.usembassy.org.uk; Tube: Bond St.). Hours are Monday to Friday 8am to 5:30pm, Saturday 10am to 4pm. However, for passport and visa information, go to the U.S. Passport and Citizenship Unit, 55-56 Upper Grosvenor St., London, W1 (tel. 020/7894-0563; Tube: Marble Arch or Bond St.). Passport and Citizenship Unit hours are Monday to Friday 8:30am to 12:30pm.

The Canadian High Commission, Macdonald House, 38 Grosvenor St., London, W1 (tel. 020/7258-6600; www.international.gc.ca/Canada-europa/united_kingdom; Tube: Bond St.), handles visas for Canada. Hours are Monday to Friday 8 to 11am for immigration services, and 9:30am to 1:30pm for passports.

The Australian High Commission is at Australia House, the Strand, London, WC2 (tel. 020/7379-4334; www.australia.org.uk; Tube: Charing Cross or Aldwych). Hours are Monday to Friday 9am to 5pm; for immigration services, hours are 9 to 11am, and for passports, 9:30am to 3:30pm.

The New Zealand High Commission is at New Zealand House, 80 Haymarket at Pall Mall, London, SW1 (tel. 020/7930-8422; www.nzembassy.com; Tube: Charing Cross or Piccadilly Circus). Hours are Monday to Friday 10am to 4pm.

The Irish Embassy is at 17 Grosvenor Place, London, SW1 (tel. 020/7235-2171; http://ireland.embassyhomepage.com; Tube: Hyde Park Corner). Hours are Monday to Friday 9:30am to 1pm and 2 to 5pm.

Emergencies -- Dial 999 for police, fire, or ambulance. Give your name, address, and telephone number and state the nature of the emergency.

Holidays -- Britain observes New Year's Day, Good Friday, Easter Monday, May Day (first Mon in May), spring and summer bank holidays (the last Mon in May and Aug, respectively), Christmas Day, and Boxing Day (Dec 26).

Hot Lines -- These emergency numbers exist in London. If you're in some sort of substance abuse or legal emergency, call Release (tel. 020/7729-9904), open Monday to Friday 11am to 1pm. The Rape and Sexual Abuse Hotline (tel. 0845/122-1331) is open daily, Monday to Friday noon to 2:30pm and 7 to 9:30pm, and on weekends and bank holidays 2:30 to 5pm. Alcoholics Anonymous (tel. 020/7833-0022) answers its help line daily 10am to 10pm. For issues related to sexual health and sexually transmitted diseases, call the Sexual Health Information Line at tel. 0800/567-123.

Internet Access -- It's hard nowadays to find a city that doesn't have a few cybercafes. Although there's no definitive directory for cybercafes -- these are independent businesses, after all -- two places to start looking are at www.cybercaptive.com and www.cybercafe.com.

Legal Aid -- The American Services section of the U.S. Embassy will give you advice if you run into trouble abroad. They can advise you of your rights and will even provide a list of attorneys (for which you'll have to pay if services are used). But they cannot interfere on your behalf in the legal process of Great Britain. For questions about American citizens who are arrested abroad, including ways of getting money to them, telephone the Citizens Emergency Center of the Office of Special Consulate Services in Washington, D.C. (tel. 202/647-5225). Citizens of other nations should go to their London-based consulate for advice.

Lost & Found -- Be sure to tell all of your credit card companies the minute you discover your wallet has been lost or stolen, and file a report at the nearest police precinct. Your credit card company or insurer may require a police report number or record of the loss. Most credit card companies have an emergency toll-free number to call if your card is lost or stolen; they may be able to wire you a cash advance immediately or deliver an emergency credit card in a day or two. American cardholders can call the toll-free numbers below in case of an emergency -- Visa at tel. 0800/891-725, American Express at tel. 0800/587-6023, and MasterCard at tel. 020/7557-5000 (the latter is not a toll-free number).

If you need emergency cash over the weekend when all banks and American Express offices are closed, you can have money wired to you via Western Union (tel. 800/325-6000; www.westernunion.com).

Mail -- An airmail letter to North America costs 56p ($1.12) for 10 grams; postcards also require a 56p ($1.12) stamp; letters generally take 7 to 10 days to arrive in the United States. The British postal system is among the most reliable in the world so you don't need to depend on Federal Express or some other carrier unless you're in a great hurry.

Newspapers & Magazines -- In London the Times, Daily Telegraph, Daily Mail, and Guardian are dailies carrying the latest news. The International Herald Tribune, published in Paris, and an international edition of USA Today, beamed via satellite, are available daily (USA Today is printed as a newsletter). Copies of Time and Newsweek are sold at most newsstands. Magazines such as Time Out and Where contain useful information about the latest happenings in London.

Police -- Dial tel. 999 if the matter is serious. Losses, thefts, and other criminal matters should be reported to the police immediately.

Smoking -- As of July 1, 2007, a smoking ban went into effect in England. Smoking is now banned in all indoor public places such as pubs, restaurants, clubs, and hotels, although hotels can set aside some rooms for smokers.

Taxes -- To encourage energy conservation, the British government levies a 25% tax on gasoline (petrol). There is also a 19.5% national value-added tax (VAT) that is added to all hotel and restaurant bills and is included in the price of many items you purchase. This can be refunded if you shop at stores that participate in the Retail Export Scheme (signs are posted in the window).

Time -- Britain follows Greenwich Mean Time (5 hr. ahead of Eastern Standard Time). For most of the year, including summer, Britain is 5 hours ahead of the time observed in the Eastern United States. Because of different daylight saving time practices in the two nations, there's a brief period (about a week) in autumn when Britain is only 4 hours ahead of New York and a brief period in spring when it's 6 hours ahead of New York.

Tipping -- For cabdrivers, add about 10% to 15% to the fare on the meter. However, if the driver loads or unloads your luggage, add something extra.

In hotels, porters receive 75p ($1.50) per bag, even if you have only one small suitcase. Hall porters are tipped only for special services. Maids receive £1 ($2) per day. In top-ranking hotels, the concierge will often submit a separate bill showing charges for newspapers and other items; if he or she has been particularly helpful, tip extra.

Hotels often add a service charge of 10% to 15% to most bills. In smaller bed-and-breakfasts, the tip is not likely to be included. Therefore, tip people for special services, such as the waiter who serves you breakfast. If several people have served you in a bed-and-breakfast, you may ask that 10% to 15% be added to the bill and divided among the staff.

In both restaurants and nightclubs, a 15% service charge is added to the bill, which is distributed among all the help. To that, add another 3% to 5%, depending on the service. Waiters in deluxe restaurants and nightclubs are accustomed to the extra 5%. Sommeliers (wine stewards) get about £1 ($2) per bottle of wine served. Tipping in pubs isn't common, but in wine bars, the server usually gets about 75p ($1.50) per round of drinks.

Barbers and hairdressers expect 10% to 15%. Tour guides expect £2 ($4), though it's not mandatory. Gas station attendants are rarely tipped, and theater ushers don't expect tips.

Toilets -- They're marked by PUBLIC TOILETS signs in streets, parks, and Tube stations; many are automatically sterilized after each use. The English often call toilets "loos." You'll also find well-maintained lavatories in all larger public buildings, such as museums and art galleries, large department stores, and railway stations. It's not really acceptable to use the lavatories in hotels, restaurants, and pubs if you're not a customer, but we can't say that we always stick to this rule. Public lavatories are usually free, but you may need a small coin to get in or to use a proper washroom.

Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.