Ask HN: How Long Can a DE C-Corp Delay Foreign Qualification Filing in CA?

Just incorporated in Delaware in order for a few of us to be able to split equity while we build our software, and assign the IP to the company. We do not expect to be doing any transaction in CA (customers, suppliers, etc...) for a while as we write our code, and it is quite possible that we won't launch until 2019. We have no office, no employees.

Do we still have to register in the state of CA w/ foreign qualification filing right away, even though we're likely to just be building software this year, or can this be delayed until we start "open up the service to the public" (or perhaps there is a criteria that defines another more appropriate time)?

I've read the "official rules" but it seems like they may be a bit open to interpretation as far as "transacting intrastate business". I imagine I'm not the only one with this type of structure and wonder what others do/did.

Thanks in advance!