Can you add our tagline to the logo?
I strongly recommend that the tagline be treated as a separate piece of artwork. It should be a part of your Visual Vocabulary,which acts as the visual sidekicks to your logo (the superhero of your brand). A Visual Vocabulary helps your logo tell more of your story, offers more visual elements to establish consistency across your brand, and allows your brand to have visual flexibility from one marketing piece to the next.
If you do include the tagline in the logo, it can affect the overall scalability of the logo – because the logo will have to remain large enough to have the tagline be legible in all applications. If the tagline is a part of the Visual Vocabulary, it can add visual interest by being placed in a different area than the logo (for example, along the bottom of your letterhead). It also can always appear at a large enough size to be read. And, if you change your tagline, you won’t also have to change your logo.
Itypically develop a tagline treatment along with the rest of your Visual Vocabulary during the design process for your other design pieces – which usually consists of a business card and some other marketing materials. Developing it in practice helps to ensure that the Visual Vocabulary will be not just pretty, but also effective.