Value-Added-Tax 'VAT' is not charged because the company a) sells services and b) is small enough to not be eligible. This means you pay less.
Nearly all customers who ask for a VAT number reside in Mediterranean countries where VAT fraud is rife.
VAT frequently asked questions
What is your VAT number?
There isn't one because the company, Farrant Consulting Ltd, is not required to be VAT registered because the turnover is below the VAT threshold (£85,000).
Why isn't your VAT number on the invoice?
In our country we have a law about online market places which says we must have a VAT number.
See above. That law is not UK law and even if it was it is for electronics, not services.