In Hong Kong, local calls from private phones are free. Public coinphones cost HK$1 for five minutes, and credit card phones considerably more. For overseas calls, buy discount phone cards: you dial an access number, enter a PIN supplied with the card, and then dial the overseas phone number; costs are just HK$1-2 per minute. The cards, sold in newsagents and small stores, are region-specific, so shop around until you find the right one.

For mobiles in either SAR, buying a local SIM card (with a new phone number) is the cheapest option, though some can’t handle calls to the US or Canada.