According to the bank, 16% of respondents said they would not be able to afford such an increase, while more than a quarter, or roughly 27%, would need to review their budget.
“The ultimate goal of most Canadians should be the elimination of debt, but the first step needs to be getting rid of bad debt,” said Chris Buttigieg, senior manager of wealth planning strategy at BMO, “which has the potential to destabilize a household's financial situation.”
Another 26% said they would be concerned, but could probably handle it.
Such an increase would be generated in the case of a three percentage point hike in interest rates - from 2.75% to 5.75% - on a $300,000 mortgage with a 25-year amoritization period.
Given that interest rates are likely to increase in the foreseeable future, the bank said there was no better time to put together a detailed debt management plan.
A report by Statistics Canada last month found the ratio of household credit market debt to disposable income climbed in the second quarter of 2015 to 164.6%, up from 163% in the first three months of the year.
That means Canadians owed nearly $1.65 in consumer credit and mortgage and non-mortgage loans for every dollar of disposable income.
The report by BMO's Wealth Institute found that almost half of Canadians, 47%, believed that the high level of debt in Canada has been influenced by soaring real estate values, while 40% believed it has been influenced by low rates.
Files from The Canadian Press