999 (emergency telephone number)

The pan-European 112 code was introduced in the UK in April 1995 with little publicity. It connects to existing 999 circuits. The GSM standard mandates that the user of a GSM phone can dial 112 without unlocking the keypad, a feature that can save time in emergencies but that also causes some accidental calls. All mobile telephones will make emergency calls with the keypad locked. Originally a valid SIM card was not required to make a 999/112 emergency call in the UK. However, as a result of high numbers of untraceable hoax calls being made, this feature is now blocked by all UK networks. Most UK mobile telephone handsets will dial 999/112 without a SIM inserted (or with a locked/invalid SIM), but the call will not be connected. Following the blocking of SIM-less calls, in 2009 the UK networks introduced emergency call roaming. This allows a user with a valid SIM of a UK network to make emergency calls on any network for which they have coverage.

Question: can you phone 999 without a sim card
Answer: no