Millions of people avoid talks about finances with their spouse for fear the conversation will get heated, according to Prudential.
The group's research has revealed 4.2 million over-40s have never discussed financial planning with their partner.
Fifteen per cent said they dodged such conversations because they think it will make them feel uncomfortable, while 23% admitted they fight over money.
The research on 2,002 over-40s in a relationship added, for those who do discuss finances, the majority neglect long-term issues.
Everyday costs and household bills are regularly addressed by the majority of couples - 60% and 52% - respectively, while only 16% said they considered retirement income and pension planning.
Vince Smith-Hughes, retirement expert at Prudential, said: "It really pays to be honest about your financial situation.
"Being open about discussing long-term financial planning as early as possible will help couples to ensure they can enjoy a comfortable retirement together."
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