090 is not a country code. Numbers inside a country start like this: AIS (Thailand), Metfone (Cambodia), Tele2 (Croatia), Athlone (Ireland) 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 |
|---|---|---|
 AIS · Thailand | +66 90 … | 090 … |
| DTAC · Thailand | +66 90 … | 090 … |
| TOT Mobile · Thailand | +66 90 … | 090 … |
| 1 more in Thailand | ||
 Metfone · Cambodia | +855 90 … | 090 … |
 Tele2 · Croatia | +385 90 … | 090 … |
 Athlone · Ireland | +353 90 … | 090 … |
| Athlone/Ballinasloe/Portumna/Roscommon · Ireland | +353 90 … | 090 … |
| Ballinasloe · Ireland | +353 90 … | 090 … |
| 2 more in Ireland | ||
 KDDI · Japan | +81 90 … | 090 … |
| NTT Docomo · Japan | +81 90 … | 090 … |
| Okinawa Cellular · Japan | +81 90 … | 090 … |
| 1 more in Japan | ||
 Zain · Sudan | +249 90 … | 090 … |
 Umeå · Sweden | +46 90 … | 090 … |
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.