Knowing when to use head voice ?

does A higher note always mean head voice ? Or is there times where singing that higher note in chest voice ( if the person can hit it) acceptable ? 

How high is the note? Some notes perceived as high can still be sung in chest voice. If it really is high (for your range/voice type), usually the healthier option would be to use mixed voice. Most pop and rock singers who are singing high notes with power are using their mix!