Most tattoos will NOT require a touch-up IF the tattoo is properly cared for during the healing process.  Once you leave the shop, it is YOUR responsibility to follow the aftercare instructions provided by your tattoo artist and heal your tattoo well. 

The number 1 reason a tattoo will require a touch-up is if the tattoo was picked at.  Using products other than what your artist told you to use, applying too much (or too little) ointment, wrapping the tattoo, allowing people or animals to touch it, submersing the new tattoo in water, exposing the tattoo to chemicals or other elements, etc. will also cause the tattoo to heal poorly.

Because these instances are NOT the fault of the tattoo artist, there is a charge for most touch up work.  

Some tattoos MAY require a touch up due to the area tattooed, and you will be told if this is the case at the time of your appointment.  These typically include cover-ups, fingers, hands and feet.  The cost of the touch up for these types of tattoos is typically figured in to the initial cost.  Again, you WILL be told if you should come back in or send a photo after the tattoo has COMPLETELY healed to see IF a touch up is even needed.  

Touch-ups are done by appointment only.   Touch-ups start at $20 (unless you were told it may be necessary), depending on how well (or poorly) the tattoo was treated during the healing process.

If you want your tattoo to look good long-term and want to avoid paying to touch it up, it is important that you follow your tattoo artist's aftercare EXACTLY as prescribed.