Cleaning subcontractors work under the primary cleaning contractor to help shoulder a project's workload. Subcontractors shouldn't be confused with employees, as they are self-employed business owners in their own right -- the primary contractor is merely subbing out the work he can't handle himself. Being eligible to take on subcontracting work means first becoming a contractor yourself.

Choose Your Specialty

Decide where you feel most comfortable working. Maid service usually describes cleaning personal homes, while janitorial service applies to cleaning business offices. You may choose to specialize; carpet cleaning and pressure washing are viable options, especially when subcontracting for a cleaner who doesn't own a carpet cleaner or pressure washer. Consider also that home cleaning typically takes place in the daytime, while the homeowners are at work, and business cleaning often occurs at night, when the workers and clients have gone home. You can even choose to work in multiple fields; versatility will broaden the types of subcontracting work you can do.

Make It Legal

Call your local Chamber of Commerce to find out your state's requirements for obtaining a business license, or check out the Small Business Administration website for state-by-state information. Consider incorporating or being a limited liability business; this way, if an accident damages a client's property, your business will be held responsible, not you. Getting bonded and insured is also smart, though not always necessary. It puts your clients at ease and covers you in case of accidents or a grab-happy employee. Business clients may even require insurance.

Get Your Supplies

Even if you're working for another contractor, you still need to provide your own tools and supplies. Buy basic cleaning supplies at janitorial supply, home improvement or wholesale stores. In addition to floor cleaners, wood polish, antibacterial cleaners, glass cleaner, computer duster and bleach, you need supplies like a commercial mop and bucket, commercial vacuum cleaner, broom, brushes, scraper, trash bags, paper towels and rags. Get a trash container and a sturdy toolbox or pushcart to carry all your supplies.

Create Your Style

Sure, you may be cleaning after other people for a living, but that doesn't mean you can't do it in style. Choose your business name when you got licensed, and pick a simple uniform and have your business name embroidered to it. Design eye-catching business cards. Use document software to create professional estimates and invoices -- no hand-written estimates or scribbled invoices. Presenting yourself as a competent professional will make other contractors more comfortable working with you.

Get the Word Out

Marketing is the lifeblood of any business. Prepare an elevator pitch: a sales presentation that sums up who you are and what you have to offer in 20 to 30 seconds. Contact other cleaning businesses in your area to let them know you're available to subcontract for them. Create a brochure to leave with them, along with your business card. Visit new construction sites, where heavy cleaning takes place, and ask who's handling the cleanup. Contact that cleaner or leave your business information on site for the cleaner to contact you.