Those who owe allegiance only to themselves or whoever is paying for their services.

Privateers

Smugglers
A smuggler was an individual who dealt with the secret exchanged shipment of goods to evade restrictions or tax fees. The items shipped were often considered contraband, and highly illegal. Smugglers would sort all kinds of illegal merchandise into forbidden areas, breaking any law that stood in their way regardless of who made it. They would then sell their cargo on the black market, deliver it to a client, or use it themselves.

Bounty Hunters
Bounty hunters were individuals who could be hired to capture or kill a designated target. The target would have a price or bounty on their heads that would be collected by the bounty hunter upon successful capture or proof of death. Bounty hunters would sometimes team together as part of a larger mission or to handle dangerous targets.
A bounty hunter was an individual who could be hired to capture, hunt or eliminate a designated target if such target had a price or bounty on their heads that could be collected by the bounty hunter, either capturing or killing the target, depending on their clients' wishes. For the right price, most bounty hunters had no morals and did everything for the money. Aside from the highest bidder, bounty hunters were only loyal to themselves.
Some bounty hunters acted like mercenaries and were hired to do jobs other than tracking down bounties. Hutts often kept these mercenary hunters on retainer so as to have more experienced and capable bodyguards protecting them.

Mercenaries
A mercenary (merc for short), sometimes also called soldier of fortune, hired gun, or free lance, was a soldier who fought or worked in other ways (mostly in those involving violence) for any faction in exchange for a desirable amount of money. Sometimes, the word mercenary was used as a derogatory term for someone who valued credits over other things, such as ideals or kinship.

Fixers
Fixers were individuals who were hired to unravel difficult situations. Like the gang arbitrators, they displayed diplomatic skills, but they were also capable of using aggression if necessary.