I am doing the initial setup of my 3CX, current on free version but will purchase enterprise next month. I wanted to use 4 digit extension numbers for my virtual extensions, but the setup tells me I can only use 3 digits. I've seen forum questions about 2 and 4 digit extensions so I know it's possible but can't find a setting to change. Is this a restriction of the free version, or is tehre a setting somewhere? Can I mix 3 and 4 digit extensions? Gary.