To call Dubai from abroad you need to dial the international country code for United Arab Emirates which is +971 and then you dial the area code followed by the local number. Local numbers are composed of seven digits.
Landline area codes are two digit numbers. The area code for Dubai is 04. Other area codes are
02 - Abu Dhabi
06 – Ajman
06 – Sharjah
06 - Umm al-Quwain
07 - Ras al-Khaimah
09 - Fujairah
When calling an area from abroad, you skip the 0 after dialling the country code. E.g., to call Dubai from abroad you dial +971 + 4 + local number. To call a local number from within UAE the 0 of the area code should be kept.
When calling abroad from Dubai, dial 00, then the country code, city code and the local number.
If you wish to call within Dubai, you can forget about the area code and dial only the local number.
To find a local number you might consult the Yellow pages.
Mobile phone prefixes
Mobile phones in UAE have their own prefixes. At the moment these are 050, 055 and 056. To call a mobile number from abroad, the 0 at the beginning of the prefix should be left out. If you call a mobile number from within the UAE, the 0 should be kept.