Legally, you can work jointly and market yourself to customers as team without forming a partnership or LLC. The only restriction is, don't lie to customers. So present yourself as a team, but not as a single business; if customers ask about the arrangement, describe it honestly and accurately.The above said, there are advantage to forming an LLC, chief of which is the liability protection it affords you. You may wish to consider forming an LLC to protect personal assets from business debts or liabiltiy. You can always include provisions for dissolving the LLC if either of you want out.