Double demerits kick in tomorrow - what does it mean for you?

As people across Australia begin to slow down ahead of Christmas, drivers across the country are warned to watch their speed as double demerit points kick into gear.

The penalties vary state-by-state, so here's what you need to know depending on where you live.

NEW SOUTH WALES

In NSW double demerits kick in at midnight on December 20 and are in place for a full 13 days until the end of January 1.

Double demerits apply to speeding, seat belt, motorcycle helmet and – of course – mobile phone offences during this period.

AUSTRALIAN CAPITAL TERRITORY

The same rules apply in the ACT as in NSW.

While the points lost for an offence are doubled – the fines are not.

WESTERN AUSTRALIA

The double demerits period is even longer in WA, starting on December 20 and ending on January 5.

Penalties such as drink or drug driving, failing to wear a seatbelt, running a red light, using a mobile phone and speeding all fall under the scheme.

QUEENSLAND

Queensland has a double demerits system, but not for specific dates in the year.

Instead, double demerits apply to drivers who have already committed one driving offence in the same 12-month period.

VICTORIA, SOUTH AUSTRALIA, NORTHERN TERRITORY AND TASMANIA

Victoria, South Australia the Northern Territory and Tasmania do not have a double demerits scheme.

Usual penalties and fines apply to offences committed during the Christmas holiday period.