"need not take" is correct and usable in written English.
It is an idiomatic phrase, which means "not necessary": For example: If you have a good understanding of the material, you need not take the exam.
But the rebuilding need not take long.
Mr. Thompson need not take this approach.
But music festivals need not take the completist heritage route.
Chinese assertiveness need not take the form of military aggression against Russia.
Brussels need not take charge of tax and spending, nor need Eurobonds cover all government debts.
If that is done, clear benefits may result, and damaging treatments need not take place.
In reality, the position has been eviscerated, and you need not take my word for that.
Legal reasoning, positivism says, is merely descriptive and need not take account of morality.
They need not take second place to Internet access, language programs and homework help.
She has won so many super-G races easily, it might have appeared she need not take excessive risks Saturday.
That is unlikely to occur overnight, but with courage and single-mindedness, it need not take years.
