How do I know if it is safe to use a logo?

Can we use a logo+name for our product even if other companies use it? We are in an industry which has no other business using the logo, but there is a clothing company, and probably some other companies, that use it. It includes a very popular/common image of a diamond.

How do you know, as a business, when to register a trademark? I read that it can cost up to $1000 - an expense that doesn't make sense for us at this time. What I'm worried about is if we start to make money and somebody decides that we "stole" their logo. We are about to "go public" (in the sense of launching the product, not stocks) and I would like to be confident that we won't have to change the logo down the line.

I am very grateful for any experience or suggestions.

To a certain extent this depends on the country you are in. The main test that tends to be applied is to ask if it would be "reasonable" for the man on the street to confuse the one brand or product for another.

It may be worth investigating if other companies in other sectors use an icon that is similarly styled. If there are many companies using a diamond style logo then I would hazard that you are in the clear however if there is just one other then they may feel, rightly or wrongly, that you are using the recognisability of their logo to enhance your own. If they do you will need to defend yourself and with the best will in the world this will cause your new business to suffer.

The question you should be asking (with evidence from the market place) is not if legally you are safe but if perceptibly to other logo users you are safe.

It would be better to have no wars to fight to start with.

If this is an unprotectable logo, (commonly used), then your rivals could as easily use it and you would be unable to stop them.

Then there is the question of uniqueness. Will your customers think you unique?

If the answer is no then you might want to re-think. The fact that you have asked suggests that you are already having the very important second thoughts.

I hope I have given you some good food for thought and wish you all the very best with your venture.