become avast partner, reseller

I am unable to register without VAT number. I am interested to become reseller and want to offer my customer paid service instead of free.

Start a business, get a vat (tax) number and register.

so its means no business under £70000 per year, because needs at least £70000 business per years to get VAT number.

That figure is the mandatory figure for having to become VAT registered - when I had a franchise the company I had the franchise with insisted all franchisees had to be VAT registered.

As far as I’m aware, you can voluntarily apply to be VAT registered (at least you used to be able to do it) even if you are under the mandatory figure. Being VAT registered can be a pain, more hassle than it is worth at times (being able to reclaim VAT paid in relation to the business), against having to charge it and account for it.

I sold me franchise some time ago and I de-registered for VAT - so I’m not exactly familiar with existing VAT rules.

vat rules depend on the country you live in.
I would say call them and ask what is possible or ask the chamber of commerce.

Given the OP quoted figures in £ UK Pounds - my comments are UK VAT related, though from some time ago.