What is the mailing address and fax number for Dallas Colleges Online? September 10, 2015 16:20 Updated Follow Dallas Colleges Online9596 Walnut St.Dallas, TX 75243 Fax: 972-669-6409 Related articles I'm a veteran and have questions about my benefits. How do I know which college I will receive credit from for my Dallas College Online class? Express.dcccd.edu says "Please add at least one course!" Why? How To Get Your Student Identification Number How do I file a degree plan?