Lawyers are trying to get in touch with hundreds of thousands of people who are owed money through a class-action lawsuit against Veterans Affairs.
The suit was launched after the Office of the Veterans Ombud found the government had been improperly calculating the disability benefits and pensions of its clients starting in 2003.
The government reached a settlement in January that is worth up to $817 million.
The problem was uncovered when the ombud looked over the department's paperwork after the government made changes to the disability award in 2016.
It discovered Veterans Affairs had been failing to factor in the provincial basic tax credit in calculating provincial income tax, but when the department later realized and corrected the error, it did not notify or reimburse people who were underpaid.
At the time, the ombud believed around 270,000 veterans were shortchanged some $165 million in what it deemed an "accounting error." The department pledged to issue corrective payments in 2018.
Michel Drapeau's firm was among five law firms that eventually brought the class-action lawsuit in 2019.
The suit also claimed that Veterans Affairs had made other miscalculations, including failing to index payments to inflation.
"When we looked at it, we found in fact there were significantly more benefits that had not been properly indexed over a longer period," he said.
Drapeau said the miscalculations actually went on for 21 years, from 2003 to 2023, meaning the number of eligible veterans was significantly more than initially believed.
Around 117,000 military and RCMP veterans who have a benefits or payment relationship with Veterans Affairs will get payouts from the department directly before December.
Another 215,000 eligible people have since died, and Drapeau said if their surviving family members don't file a claim they will miss out on the payment.
The eligible claimants could be surviving spouses, common-law spouses, children, parents, siblings, nieces or nephews, or the veteran's estate.
"We're trying every means possible to let them know," Drapeau said.
He said they've already launched a search for people on social media, through advertising campaigns and by contacting the Royal Canadian Legion. In addition, a mailout has been sent to the last known addresses of around 200,000 people.
On average, claims are worth about $2,500. According to the Federal Court settlement, 40 people are eligible for payments over $35,000 but most payments are less than $5,000.
Management and consulting firm KPMG has been hired to help people file their claims, which can be done online.
The federal government is responsible for the cost of administration of the claims and KPMG is not getting funding from the settlement itself.