033 is not a country code. Numbers inside a country start like this: Team Telecom Armenia (Armenia), Kolkata, West Bengal (India), Chachoengsao/Chon Buri/Rayong (Thailand), Prijepolje (Serbia) and others. The first digit 0 is the trunk prefix for domestic calls and is dropped from abroad.
Have the full number? Check it in the number lookup.
| Area or operator | From abroad | Inside the country |
|---|---|---|
 Team Telecom Armenia · Armenia | +374 33 … | 033 … |
 Kolkata, West Bengal · India | +91 33 … | 033 … |
 Chachoengsao/Chon Buri/Rayong · Thailand | +66 33 … | 033 … |
 Prijepolje · Serbia | +381 33 … | 033 … |
 Amersfoort · Netherlands | +31 33 … | 033 … |
 Thun · Switzerland | +41 33 … | 033 … |
 Açucena - MG · Brazil | +55 33 … | 033 … |
| Água Boa - MG · Brazil | +55 33 … | 033 … |
| Águas Formosas - MG · Brazil | +55 33 … | 033 … |
| 71 more in Brazil | ||
If a number starts with +, the first 1–3 digits are the country code. If it starts with 0 (8 in Russia and Kazakhstan), it is a domestic number: an area or operator code follows, and from abroad the 0 or 8 is replaced with + and the country code. The same digits can mean different places, so where the call came from matters.