I'm not aware of any formal definition of "startup". If one exists, I'd love to hear about it.

I think about a "startup" in this way:

• The term applies to high-growth companies and companies with intentions / aspirations / hopes of high growth.
• If such a company has negative cash flow and lives off venture capital, then it is a startup no matter how large or old it is. For example Twitter is still a startup IMHO, Facebook was a startup for a long time.
• If such a company has a positive cash flow, then it is a startup until it reaches 100 employees or 4 years of doing business, whichever comes first.

If a company has been doing something for 4-5 years and is profitable, then it is not a "startup" IMHO -- it's a successful company.

A perhaps more useful way of defining startup could be:

• Startup: Any company before product / market fit, and any company with product / market fit which is expanding and financing this expansion with equity.
• Growth company: Any company which has product / market fit, and finances itself by other means than selling equity (i.e. organic growth, loans).

If youve been at the coal face for a good 4 to 5 years do potential investors want to hear that your still in startup mode

Almost certainly not. They might not dislike the company being called a startup, but they would want it to be in a "scale up mode" or "transitioning to mainstream market" mode or something similar.

I almost think it is on your frame of mind.

A startup has a very particular culture, as there is so much energy and innovation taking place in a flat hierarchy.

So, even though you may be making a profit you may still be a startup, until you are either acquired or have been around for a while, and become more mature, and the culture of the business will have become mature.

there are various stages in company growth and there is much written about it on the internet or textbooks. opinions and stages differ slightly from author to author. I personally like to think that the goal of startup is to prove the business concept and start bringing money into the bank. this means that there are customers who actually pay for the product/service and there is minimum viable product. once the startup achieves the goal its not necessarily startup anymore.