It is now law for children in vehicles to be correctly secured in an approved child restraint until their seventh birthday.

Changes to car restraint laws come into effect today, requiring children to use an approved restraint until they turn seven, and seven-year-olds to use a booster or car seat if one is available.

Travel Safe coordinator Cindi Feder, Plunket car seat technician Donna Tuck (with daughter Layla) and Sergeant Mike Owen working together to promote child safety.

The new law extends the mandatory age by two years. Previously, children between five and seven years old were required to use a restraint only if the vehicle had a seat or cushion.

An approved restraint is one that suits the child's height and weight, as specified on the seat.

This can be a harnessed child restraint, a full backed booster seat, or a half booster cushion.

As the new law comes into play, Western Bay of Plenty road policing manager Senior Sergeant Ian Campion says Police will be taking a focussed approach to make sure parents and caregivers are obeying the rules.

'We'll obviously be providing a small window of grace, but after a week or two we will be issuing infringement notices.

'In this day and age there is no excuse for not having a child restraint. If you can't afford to purchase one, then they are available through the Plunket rental service at very reasonable rates.”

After four months of warnings and public education, Ian expects the transition will be smooth.

'There's been a lot of publicity around it and my expectation is that there should be a big uptake in terms of compliance.”

He also takes this time to remind drivers they are responsible for ensuring passengers under the age of 15 are restrained correctly. By ignoring this legal requirement they are making a decision for young people that could injure or kill them, he says.

The rule change was agreed by Cabinet in 2012 and signed in June this year, providing parents and caregivers four months to ensure they have appropriate child restraints, such as booster or car seats.

More information about approved standards for child restraints and list of certified child restraint technicians, who can provide expert advice, can be found at www.nzta.govt.nz/childrestraints

Below are some frequently asked questions Plunket receives about car seats and the answers:

What does a booster seat do?

A booster seat lifts your child up to a position where the vehicle safety belt will sit against their body in the best position to protect them from injury in a sudden stop or crash.

What type of booster seat is best for my child?

When purchasing a booster seat, the shape of the booster must:

Allow the shoulder belt to cross the centre of the shoulder - not be against their neck

Allow the shoulder belt to stay in contact with the child's torso as it goes down across the front of their body - you don't want gaps between the safety belt and your child

Allow the lap belt to remain in position across the top of the thighs and not move up around the abdomen.

When is my child tall enough to move from their booster seat?

Plunket encourages parents and caregivers to keep children in their booster seat until they are tall enough (about 148cm) to sit on the vehicle seat with the adult safety belt positioned correctly. For some children this may not be until they are 11 or 12 years old.

Plunket recommends a full booster seat:

A full booster seat is one with a back; this type of booster seat is the most commonly seen. It usually has a headrest that can be moved up as your child grows. Full booster seats provide good side impact protection and also help prevent the child leaning sideways.

Do not use a booster seat with just a lap belt:

Booster seats cannot be used with a lap belt. Lap belts do not restrain the upper body in a crash and therefore the child is thrown forward and the seatbelt can cause serious and potentially life threatening injuries