Hi Lep,
Driving without a licence is a serious traffic offence. Why was the driver without a licence? Was it suspended? Were they from overseas? Did they never obtain a licence?
If you are charged with just driving without a licence, you could be fined or be imprisoned up to 18 months, depending on your previous driving history, criminal history and circumstances of the offence (
Road Traffic Act 1974 (WA)
section 49). Given you were in an accident, you could be further charged with careless driving, or its more serious offence of dangerous driving. These will incur higher penalties.