Consumers will have until June 2019 to claim compensation for payment protection insurance mis-selling under proposals outlined by the City watchdog.
The Financial Conduct Authority (FCA) confirmed plans to launch a marketing campaign from next June, which will be funded by Britain's banks, to raise awareness of the 2019 deadline for claims to be submitted.
It will see a line drawn under the payment protection insurance (PPI) scandal, which has been the costliest yet for the financial services industry, with the total bill now running at a mammoth £24 billion.
FCA chief executive Andrew Bailey said: "Putting a deadline on PPI complaints will bring the issue to an orderly conclusion in a way that protects both consumers and market integrity."
He added: "We will ensure that our communications campaign will engage with all those who could be affected, particularly vulnerable consumers."
It will consider further feedback on its proposals for the June 2019 deadline until October 11.
The FCA admitted the deadline is later than first expected and later than a number of banks wanted, having previously put forward a cut-off in spring 2018.
But it said it gives time to prepare the marketing campaign and get plans in place for the deadline.
PPI is still the most complained-about financial product, with recent figures from the Financial Ombudsman Service (FOS) revealing that as many as 4,000 new complaints are received every week.
The FOS said it received 188,712 new PPI cases in 2015-16, making up just over half of its workload in the last financial year.
Around one in five PPI cases are resolved within three months.
Half-year results from Barclays last week revealed another £400 million charge for PPI in the second quarter, taking its total provisions to £7.8 billion.
Lloyds Banking Group, which also posted figures last week, made no extra PPI provisions, but it continues to receive 8,500 PPI claims each week.
Its total cost of the scandal dwarfs those of its rivals, with Lloyds having put by more than £16 billion so far since 2011.