Joint bank accounts can prove a bone of contention between partners, according to Abbey, with a quarter of all couples arguing over how they use the account.
One in five people have used their joint account to make purchases for themselves without telling their partner, the research showed, while almost one in four suspects their partner of plundering the account to buy something individually.
Perhaps the least controversial use of these accounts is making shared payments for amenities which benefit both partners equally, such as making mortgage payments or paying gas bills.
But one in three argued that it was not appropriate to use the money held in common for individual purchases such as games consoles or mobile phones.
Clarity over how the account should be used could help couples avoid quarrels, suggested Steve Shore, head of banking at Abbey
He added: "It's important that couples are open and honest with each other from the start and discuss exactly what the joint account rules are."
Earlier this month, moneysupermarket.com found that up to half of those set to wed this summer were planning to finance their wedding on credit, borrowing just under £8,500 on average.
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