WA drivers will soon face the harshest penalties in the country if caught on their mobile phone.

Drivers will cop a $1000 fine and four demerit points when new laws come into effect on July 1.

WA will now fall in line with Queensland, which adopted the same penalty in January, which is nearly double the next highest penalty, which is $577 in the ACT and $534 in SA but TRIPLE that of NSW which attracts $337 (but 5 demerits).

Touching a mobile with at the traffic lights in WA or holding the handset during a call will be considered a lesser offence, attracting a $500 fine and three points.

Last year, 11, 849 motorists were pinged using their phones.