In the UK, from 2008 the Voltage tolerance is widend to 230 V ±10% (i.e. between 207 V and 253 V) from pervious 230 V +10%/−6% (i.e. between 216.2 V and 253 V). However, the system supply voltage in the UK remains at exactly 240 V.

More and more countries in the world are using the 230 V standard. However, countires like Japan, Taiwan are still using a voltage between 100 V and 127 V. For the voltage of different countries, check here.