I'm starting a new startup with a cofounder. Do I need to also create a shareholders agreement or is a company constitution enough?

(I'm a small biz attorney who helps people with copyright, trademark, and other IP law, and I'm answering per U.S. law.) As soon as you take your idea and put it into a tangible format (write it down, create an infographic, record a video), then that writing/infographic/video is automatically protected by copyright law. You can record the copyright on it too, which makes it easier to protect and get damages from other people taking it. But the formula itself would be probably protected under trade secret law or patent law. Patent law obviously takes a bit more effort, because you have to apply for the patent and get your application examined by the USPTO, which takes years and $$$. Keeping it protected under trade secret law means you have to make an effort to keep it secret (which may not work if you are disclosing it as part of your marketing efforts), such as keeping it confidential and requiring NDAs. As someone else said, the other terms you use might be protected under trademark law. If a member of the public would use those terms to link your products/services with the source of the product/service (aka, your company), then they could be trademark-able. There are some state law protections for trademarks, and you can also file to register the trademark with the USPTO and get more protection. Hope that gets your started!

I'll keep try to keep this answer brief, but there are several factors and nuances that can be discussed in more depth. Where you decide to incorporate partly depends on what your future goals are with your company. Companies that plan to seek venture capital or go public typically choose Delaware as the state of incorporation, and usually choose a C-Corp. Delaware has a very well developed body of law surrounding corporate governance and that provides comfort and more certainty to future VC investors. If you're not planning to seek VC money any time soon, an LLC is a smart decision because of the tax benefits it can provide to you as the owner. It sounds like you want to grow your company on your own without outside financing. If that's the case, I would recommend forming your LLC in California. Regarding California vs. Delaware, one benefit to forming your LLC in California is that you can avoid paying a registered agent fee which can cost anywhere from $100-200 a year. If you plan to seek venture capital down the road, you can reincorporate in Delaware.

Disclaimer: I'm not a lawyer, I've never played one on TV, and it has been ages since I've stayed at a Holiday Inn. However, it sounds like you've stated clearly that your need is a lawyer who SPECIALIZES in contract law, with EXPERIENCE doing so for Digital Agencies. A great way to find someone like that is to ask other agencies that you have a good relationship with. For critical professional services like legal representation, I've always had a strong preference for a referral. Preferably from someone I know who has enough similarity in business and principles that I can reasonably expect to have the same good outcomes they've enjoyed. I'd say this is a matter of asking a few friends in the business for referrals - and then interviewing them. If you don't have friends in the business - consider searching Clarity for people with digital agency experience (rather than legal experience), and request a call to get their recommendations on counsel.

The HKG company has the same commercial law set of UK, that said, between the two it would be safer using an NDA fitting the latter.

One word: Royalties This means you generate the idea and develop it enough to look interesting to a larger company who would be willing to pay you a royalty for your idea. This happens all the time. Rock stars, authors and scientists routinely license their creative ideas to other companies who pay them a royalty. Anyone can do it. Your business, therefore, would be a think tank. You (and your team, if you have one) would consider the world's problems, see what kinds of companies are trying to solve those problems, and then develop compelling solutions that they can license from you. You have to be able to sell your idea and develop a nice presentation, a little market research and an understanding of basic trademark and patent law. The nice thing about doing this is that if you develop enough cool ideas you will have royalties coming in from a lot of different sources, this creates a stable, passive revenue stream that requires little or no work to maintain. Start in your spare time and plan on the process taking 3-5 years. Set a goal to have a few products in the market that provide enough revenue (royalties) to cover your basic living expenses. Then you can quit your day job and dedicate more time and increase the momentum. A good idea business should have dozens, if not hundreds of license contracts generating royalties. It's possible to pull this off. And it is a fun job (I'm speaking from experience).