You'll want to make sure that your chil­dren are as safe as pos­si­ble in the car, which means choos­ing a car seat suit­able for your car and the child's age/size, fit­ting the seat prop­er­ly in the car, and mak­ing sure the child is strapped in cor­rect­ly for every jour­ney.

Be­fore you start look­ing at child seats it's im­por­tant to un­der­stand the le­gal re­quire­ments-who must use child re­straints and when must they do so?

You will need to know how much your child weighs be­fore you can buy a child seat be­cause this is the main fac­tor that de­fines the dif­fer­ent groups of child seat avail­able and the chil­dren they are suit­able for.

There are lots of things to take in­to ac­count when you are choos­ing a child seat:

• Safe­ty-is the seat suit­able for your child and com­pat­i­ble with your car?

• Price-aim to buy the best seat you can af­ford tak­ing ac­count of in­de­pen­dent test, re­sults and re­views.

• Us­abil­i­ty-are the in­struc­tions clear, can you fit and ad­just the seat eas­i­ly, is your child com­fort­able in the seat and can the cov­ers be re­moved/re­fit­ted eas­i­ly af­ter clean­ing?

Weight groups

Be­fore a child re­straint can be of­fered for sale it is put through a num­ber of safe­ty and per­for­mance tests by the au­thor­i­ties, in­clud­ing crash tests us­ing a num­ber of child-size dum­mies. All seats will come with an in­di­ca­tion of the age range cov­ered but they are ac­tu­al­ly ap­proved for sale in spe­cif­ic weight groups.

In­fants

Your new­born ba­by won't be able to sup­port his or her head un­til about six weeks and won't be able sit up un­til much lat­er, so child seats for the youngest chil­dren are all rear-fac­ing, de­signed to sup­port the head, neck and back even­ly. You must not use a rear-fac­ing in­fant car­ri­er on a front-pas­sen­ger seat where there is an ac­tive pas­sen­ger airbag fit­ted. The close prox­im­i­ty of the child to the airbag could re­sult in se­vere in­jury or death if the bag is trig­gered in an ac­ci­dent. It is bet­ter to keep chil­dren in rear-fac­ing re­straints for as long as pos­si­ble. Many in­fant car­ri­ers/ba­by seats are fit­ted us­ing the adult lap-and-di­ag­o­nal seat belt while the child is re­strained in the seat by an in­te­gral har­ness. This means that these seats can be eas­i­ly moved from one car to an­oth­er-as­sum­ing the adult belts are long enough. You can al­so buy in­fant car­ri­ers that are fit­ted us­ing the ISOFIX sys­tem. Typ­i­cal­ly these com­bine a 'base' at­tached to the car and a seat that clips eas­i­ly in­to and out-of the base. The base will have a front sup­port leg to pre­vent for­ward ro­ta­tion in an ac­ci­dent.

Two-way seats

Seats that can be used rear-fac­ing for the first nine months and then for­ward-fac­ing up to three or four years may look a good idea if mon­ey is tight, but they are a com­pro­mise. They are big­ger and heav­ier than an in­fant car­ri­er so you loose all the con­ve­nience of be­ing able to car­ry the child in and out of the house in the child seat. Fit­ting in­struc­tions can be com­pli­cat­ed as well which means that two-way seats are of­ten in­stalled in­cor­rect­ly. As your child gets to around nine months, though some will be ear­li­er, it's time to think about mov­ing them out of the in­fant car­ri­er and in­to a for­ward-fac­ing seat.

Boost­er seats

Some boost­er seats, aimed at old­er chil­dren, are sup­plied with a re­move­able har­ness for younger chil­dren. Look for seats marked 'Group 1,2 and 3'. Check whether your car is fit­ted with ISOFIX an­chor­age points. Be­sides be­ing more se­cure, these ded­i­cat­ed at­tach­ment points can al­so make it quick­er and eas­i­er to fit a child seat cor­rect­ly. Look for a seat that's easy to ad­just. You'll need to ad­just the har­ness a lot to suit the thick­ness of clothes the child's wear­ing.

Com­pat­i­bil­i­ty can be a prob­lem

Few, if any, 'uni­ver­sal' child seats can ac­tu­al­ly be fit­ted prop­er­ly in every seat­ing po­si­tions in every car. Check the man­u­fac­tur­er's ap­pli­ca­tion list and ask the re­tail­er to show you how the seat can be in­stalled cor­rect­ly in your car.

Fit­ting tips

• The di­ag­o­nal part of the belt should lie across the child's shoul­der, not the neck.

• The lap part of the belt should lie across the top of the child's thighs, not around the ab­domen.

• Belts should lie flat. Avoid twists, which can in­crease in­juries in a crash.

• Nev­er pass the di­ag­o­nal part of the belt un­der the child's arm.

• Sta­t­ic rather than in­er­tia reel (au­to­mat­ic) seat belts must be used for chil­dren un­der three years (ie at the low­er end of the weight range.