Posted on August 25, 2015 at 5:00 PM
Even if you have done business with a company or organization, you do not have implicit permission to use their logo for your own promotion in your marketing materials.
Company and organization brands are the visual image presented to the world in color, logo and use of language. Each brand has a different purpose, though strength, integrity, and consistency are some of the key elements underlying most brands. The logo is the distilled visual representation of their brand.
To be sure their brand is protected, many companies and organizations trademark their logo, which is why the word used to refer to logos in the design business has been shortened to the "mark". A trademark gives extra legal protection to the company if they find unauthorized use of their logo. Even if a logo is not yet trademarked, it is still protected by copyright laws. Side note, they also often trademark their tag lines as well.
If you are not a part of that company or organization, using a logo by itself to represent you or your work is a violation of the trademark or copyright, and can be subject to legal action. In order to use another company's logo or company/organization's identity to augment your identity, what you need is written permission. Yes, those client pages, that you see filled with logos on some websites, should all have written permission to use the logos that they show.
Legal permission to use a logo can be written into a contract between businesses, but legal departments generally do not allow that text to stand in a contract.
Using a logo or mark to link to a website representing that company is acceptable, as long as you do not imply that this company endorses you without getting their permission.
Logo Mantra: Treat logos with respect.