Do I have to calculate VAT?

Ma
4

If I sell 3 broken laptops as a private purchase

Ma

No.

Br

Private sales are not subject to VAT

Do

You are (probably) not an entrepreneur, so you shouldn't be charging sales tax.

Ke

You are an entrepreneur - trader; the lappies are used professionally? There's no private sale. As a dealer, you have a 1-year guarantee.