[susan53]

You can use either. At least in British English. If you scroll back through the threads in this forum you'll find another discussion of the use of have got in American English

I have /Do you have/I don't have is the present simple of the verb have. Have (in these examples) means possess.

I've got /Have you got / I haven't got is the present perfect of the verb get. Get means obtain. The present perfect is used to express the present result of a past action. If the past action is I obtained something then the present result of that action is that I possess it.

Therefore logically [I've got = I possess.

And that leaves us with I have = I possess and I've got = I possess

So : I have = I've got = I possess - and of course the related negative/interrogative forms

The use of I've got has also been extended to cover other sorts of more metaphorical "possession" - I've got two brothers / brown hair / a meeting today /a questionetc. But the underlying rationale is the same.

However, when have does not mean possess but has another meaning (eg drink as in I usually have a coffee before I start work) then obviously have got cannot be used.