Around 400,000 policyholders whose details were supplied by Equitable without contact addresses are still due to receive payouts under the compensation scheme, which is being extended for an extra year to give more time for them to be tracked down.
The advertising campaign, which will run in newspapers and online, is to be launched in the coming weeks, a spokesman for the Equitable Life Payment Scheme said.
More than one million people were left out of pocket after the pension firm was brought to its knees more than a decade ago and around 600,000 of them have received payments so far, totalling £734 million.
In April, the National Audit Office raised fears that around 200,000 people, or up to one fifth of eligible policyholders, will never be tracked down.
Victims' campaigners also criticised the "arbitrary" cut-off point of the scheme of April 2014 - a date which the Government said today has been moved to mid-2015.
In some cases, policyholders' addresses passed on by Equitable to the compensation scheme are up to 20 years old and in other cases it has not had an address at all.
Tracing people who were members of company pension schemes which were administered by Equitable Life has been less straightforward than tracking down those who were direct customers because Equitable did not hold addresses for individual members of these company schemes.
The compensation scheme has come to agreements with trustees of company schemes, who do hold more information about these policyholders, in order to find contact addresses.
But in some cases, these policyholders who have had a pension scheme which was paid into Equitable Life have not updated their details with the trustees when they have moved on.
The age range of "lost" policyholders is thought to vary widely and while some are likely to be still of working age, concerns have also been raised that others will have died before all the payouts have been made.
National Savings and Investments (NS&I), the Treasury's partner in administering the scheme, has been working with the Probate Office to obtain the information needed to make payments to the estates of people who have died.
Campaigners the Equitable Members' Action group (Emag), which had previously pressed the Government to abandon its April 2014 deadline for the payment scheme, said it is "delighted" that the date has been extended.
Emag spokesman Paul Weir said: "It is vital that the Treasury complete the task of tracing those who are entitled to compensation and we will be working with them to assist that process."
The Government set aside a £1.5 billion pot to compensate existing and former policyholders at the society after the Parliamentary Ombudsman identified 10 instances of maladministration by regulators and Whitehall officials in relation to Equitable. The scheme was set up to compensate those who bought policies after 1992.
Financial Secretary to the Treasury Sajid Javid said: "We've made strong progress, but we want to maximise the number of people who will eventually receive payments, which is why we're extending the Equitable Life Payment Scheme to mid-2015."
Any policyholder who believes themselves to be eligible for compensation but has not yet been contacted can call the scheme directly on 0300 0200 150.