Editor’s Note: College Treps is a weekly column that puts the spotlight on college and graduate school-based entrepreneurs, as they tackle the tough task of starting up and going to school. Follow their daily struggles and this column on Twitter with the hashtag #CollegeTreps.

As a college entrepreneur who's always on the go, it's downright vital to have everything at my fingertips. Good thing for me, backpacks remain a key wardrobe staple on campus.

I have been constantly commuting between school and work -- that is, my brick-and-mortar business, Green Bean, which is about three miles away from campus. At the restaurant, I always set up my office at the corner table. Customers know me as "the blonde girl who is always working on her computer."

Though I always have something to do, I never know when I will need to work on homework, and when I'll need to focus on Green Bean. To solve this problem, and to bridge the gap between my dorm-room desk and my makeshift-restaurant office, I developed what I called my mobile office out of my very colorful backpack (see inset photo).

Over time, I recognized the tools I'd need to carry with me in order to run my business and to never get caught unable to complete a piece of work. Aside from a smartphone and a laptop, which every student entrepreneur cannot live without, the following are the most important mobile-office assets that I make certain to never leave home without:

1. Checkbook. Particularly for a brick-and-mortar business, it's important not to go anywhere without a way to pay vendors. Sometimes, no checkbook means no inventory.

Related: 4 Tips for Turning a Dispersed Team into an Asset 

2. DocuSign Ink App. With my full printer/scanner located on my dorm room desk, I needed to be able to execute documents from the road. DocuSign Ink (or any digital scanning smartphone app) provides a great UI for mobile signatures.

3. Digital Textbooks. Since being a student entrepreneur means being on-the-go, I need to be able to do homework without hauling 30 pounds of books around on my back. Digital textbooks allow me to make sure my assignments are accessible from anywhere.

4. A "to-do" folder for pending paperwork. This folder acts as my physical to-do list, full of bills that need to be paid, mail to sort, etc. Similar to a pending file folder one might find on a desk, mine hangs out in my backpack.

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Sarah Haselkorn’s colorful backpack doubles as her entrepreneurship toolkit.

Related: 3 Reasons to Be Proud of Your Brick-and-Mortar Shop 

5. Business cards. You never know when you might run into a potential customer, a funding source or an adviser, and it's important to be prepared with the right tool for exchanging information.

6. Phone charger. This might be the most important accessory within my mobile office. I spend a lot of time utilizing my smartphone away from home, so I make sure to bring my charger with me everywhere I go. I can juice up during class, or plug in while I'm working at Green Bean. A car charger is an even more ambitious and useful investment.

Related: 4 Ways to Stretch Your Startup Budget as a Student Trep  

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