This story is about an alternate universe where humans would generate tattoos at life events or turning points in their lives. I remember that part of the story had to do with some people who would go to black market areas or people and get fake tattoos similar to how it is done in real life because they were ashamed at not getting their own tattoos. These people if I recall correctly were adults and were looked down on in society compared to normal people who would get their first tattoos before adulthood.
Maybe Caste (2013) by Raelynn Fry?
Citizens of Neech (poor) and Dahn (rich) receive tattoos or marks at their Jatis or coming of age ceremony at the age of 8 years old. The marks can be scanned like a credit card, designate their career and they are "paired" for marriage...all decisions made by The Corporation.
Seventeen-year-old Karis Singh’s little brother is dying and the Corporation’s Analysis has concluded that he’s not worth saving. One thing is stopping her from going into the city (Dahn) and stealing the medicine herself—the tattooed Mark that physically bars her from entering. The only way around that is to get it altered in the Black Market— an act that carries the possibility of a horrific and slow death— guaranteeing her the access she needs.