Janitorial supply companies provide basic and advanced equipment and cleaning supplies to education institutions, government agencies, hospitals or janitorial contractors. The key to building a successful business is strong customer service and repeat customers. You can run a supply service from your home, on-line or at a brick-and-mortar storefront. If you choose to run a traditional storefront, plan to spend between $10,000 and $50,000 to get started, according to Entrepreneur magazine.

Create a business plan. Your plan should include a profile of the company and customers, janitorial supply purchasing, financial information, marketing, franchise options and insurance, at minimum. You can find templates for business plans at the Small Business Administration website.

Choose a method for delivering supplies to your customers. If you plan to open a brick-and-mortar storefront, you will need to select a location and follow municipal zoning regulations. If you choose to sell supplies online using a drop-ship method, you need a website, hosting account, e-commerce solution, a drop-ship company and a shipping account. Contact commercial real estate agents in your city to locate suitable space.

Contact your state's business registration division to request information on licensing and registration. Select a business name and conduct a search of your state's business name registration database to make sure the name is available. You can conduct the same search for an online store using a domain registration service, such as Network Solutions, WhoIs or Go Daddy. Request the application for business registration, complete the form and submit it along with the required fee.

Call your state's department of revenue to request a sales and use tax license. The license permits you to collect sales taxes from your customers and pay the state through your business's account. You will need a sales tax and use license for a brick-and-mortar or on-line storefront. You will need the Social Security number of the owner or the federal employer's identification number of the business and the NAICS code. The NAICS code for janitorial supplies is either 423850 or 453998, depending on how you plan to sell your products.

Locate a janitorial supplies wholesaler. Wholesalers provide bulk supplies at a reduced rate. You will need your sales and use tax license number or certificate to begin making purchases. Contact The Worldwide Cleaning Industry Association, The International Janitorial Cleaning Services Association or Fikes Dealers Association to locate a wholesale distributor.

Stock your store. Create a listing of supplies. Include everything from cleaning solutions, toiletries, mops and brooms, buckets and buffers. You will need to stock your location online or offline. Regardless of which one you choose, you can still use a supply wholesaler.

Market your products and services to your target audience. For example, if you would like to work with corporations, contractors or government agencies, begin an advertising campaign. Create advertising collateral such as flyers, business cards, brochures and sales letters. Contact a designer or marketing firm to begin the process. You can also place advertisements in your local newspapers and telephone directories.

Research contract opportunities. Many government organizations execute contracts with janitorial businesses. Contact your local government to request information on locating related requests for proposals.