0957 is not a country code. Numbers inside a country start like this: Kaimana (Indonesia), Isahaya, Nagasaki (Japan), Claro (Peru), Network of the World (South Sudan). 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 |
|---|---|---|
 Kaimana · Indonesia | +62 957 … | 0957 … |
 Isahaya, Nagasaki · Japan | +81 957 … | 0957 … |
| Shimabara, Nagasaki · Japan | +81 957 … | 0957 … |
 Claro · Peru | +51 957 … | 0957 … |
 Network of the World · South Sudan | +211 957 … | 0957 … |
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.