For those unfamiliar with the series, it follows accountant Lexie Noble (Morven Christie), who becomes entangled in a dangerous police operation following the brutal death of her husband.
Viewers took to X, formerly known as Twitter, to share their thoughts – and it's safe to say episode one went down a storm.
One person wrote: "#Payback what a fantastic first episode. What a spider web that is going on," while another added: "Well that was a fantastic 1st episode, I'm gripped already! #Payback."
A third person commented: "Just watched the first episode of Payback on @ITV, bloody good it is. Going to get deep."
Other viewers also praised the star-studded cast, which includes The Bay's Morven Christie, Rings of Power star Peter Mullan, and Line of Duty's Prasanna Puwanarajah.
One person wrote: "So far so good, with this cast gotta feeling it's gonna be good," while another added: "That was good. Great cast."
A third person commented: "Cracking drama and the wonderful Morven. I remember her in the first two series of #TheBay."
What is ITV's Payback about?
The six-part drama follows widowed accountant Lexie Noble, who becomes involved in a perilous police operation to topple a notorious crime lord, Cal Morris.
The synopsis continues: "With an idyllic family lifestyle in the suburbs of Edinburgh, Lexie is unaware her husband, Jared, has been laundering Cal Morris' illegal earnings on a vast scale. Jared's every move is being monitored by financial investigators DC Jibran Khan (Prasanna Puwanarajah) and DCI Adam Guthrie (Derek Riddell), who are determined to use the Noble family to bring Cal Morris to justice.
"A partner in Jared's business, Lexie is forced into working for Cal, at the same time as the police net inexorably tightens. Soon Lexie finds herself walking a treacherous tightrope between Cal and the police in which her safety, and even her life, are in grave danger."
The series is executive produced by Line of Duty creator Jed Mercurio and penned by Debbie O'Malley, who has written for shows such as All Creatures Great and Small, Call the Midwife, and Around the World in 80 Days.
On how Payback differs from other shows of its genre, Jed told ITV: "One of the things that I think makes it really distinctive is that there's a storyline about financial crime, which is quite unusual in TV thrillers but what Debbie has done brilliantly is to make it very understandable.
"Also it always relates back to the stakes of the story, which is that Lexie Noble is caught between a very dangerous organised crime gang led by Peter Mullan's character and a police organisation that are desperate to bring down his empire. Lexie is caught in the crossfire of that and however complicated the financial side of things gets we always circle back to that in a very visceral and easy-to-follow way."