In Wrong No, aspiring actor Sallu (Danish Taimoor) locks horn with his father, Haji Abba (Javed Sheikh), who thinks he's a good-for-nothing loafer. Haji Abba gives Sallu an ultimatum: find a job within a month or get ready to join the family trade, that is, being a butcher. Meanwhile, Sallu's marriage is also arranged against his will to Laila (Sohai Ali Abro), whom he despises despite her devotion to him.
(Spoiler alert) All this is too much to take for Sallu, so he hatches a plan to swap places with his lookalike, Shehreyar, a rich businessman’s grandson, whose impending arrival from Australia was broadcast on local TV. When Shehreyar lands at the Karachi airport, he is mistaken for an absconding Sallu by Haji Abba, who drags him back home and keeps him under lock and key.
Meanwhile, Sallu, who is mistaken to be Shehreyar by his grandfather’s company secretary Haya (Janita Asma), is escorted to a swanky hotel suite. He starts to enjoy the good life, leaving Shehreyar to languish in his family’s grip. How's that for a switcheroo?
Shehreyar isn’t only Sallu’s ticket out of misery. Three goons – Danish Nawaz, Nadeem Jaffri and Atif Shah – want to kidnap him for ransom to help repay a hefty loan taken from a mafia don (Shafqat Cheema). The trio soon discover that the don is out to kidnap Shehreyar for his own gain.