Can I use another company's logo on my website?
The short and conservative answer to your question on whether you can use a third party's logo on your website without getting prior consent is No.
The longer explanation of the short answer is - It is very tricky to use someone else's logo on your website because many type of Intellectual property rights are invoked.
When it comes to logos on websites, you are encroaching on both trademark fair use and copyright fair use. If the company's logo you are using is famous then this may also be recognized as a famous trademark, which adds to the complexity of the matter.
Trademark laws protect their owners from unauthorized use by others if such use is likely to lead to confusion. (will you be selling a similar product/service, will your user be confused as to the source of the product or service (assume that you are affiliated?). This is the first consideration among many.
Second, the trademark dilution doctrine, applies to famous marks and protects them from “tarnishing” , “blurring” and “diluting’ with unauthorized use. Therefore under this doctrine the scope of infringement widens if you choose to use a famous trademark logo on your site. Trademark Law Prohibits Infringement, False Advertising, Cyberpiracy, and Dilution.
In general online use of third party trademarks may lead to liability. therefore it is recommended that you do NOT use a third party trademark whether it is a logo or other type of trademark on your website. You should ALSO Seek a legal opinion from a lawyer in the country you are doing business in.
This response can not be construed as a legal opinion.