Nearly four in ten parents (37%) with children under the age of 18 have less than £100 in their account at the end of the month, while 15% tend to be using their overdraft.
The same proportion (39%) are concerned about not having enough money put aside, according to the family finance index from M&S Bank.
And nearly a third of parents don't know what the APR is on their credit card, which means they may not be using the best card to suit their needs.
However, on a more positive note, 91% were aware of exactly how much they have in their current account - but although 27% were aware there were current account charges they didn't know how much they were.
The M&S Bank research did find that financial planning is higher up on parents' list of priorities for 2014.
Over half (56%) of parents told the bank they will set a household budget for the year ahead, compared to 46% last year.
And nearly one in five (19%) parents are planning to review their finances as part of their New Year's resolutions for 2014 - this compares with just 13% in 2013.
When it comes to managing the household finances, more than a third (36%) of mums and dads are planning to share the responsibility between them. However, 30% of mums will check bank statements daily, compared to 22% of dads.
Of those who have money left at the end of the month, over a quarter (26%) plan to save it, with 30% of dads planning to save compared to 22% of mums.
Colin Kersley, chief executive of M&S Bank, said: "It's encouraging to see that parents are taking action to plan their finances for 2014 but to plan effectively families need to be aware of any interest or charges they are paying on their accounts. By understanding all of their outgoings, they can look forward to the new year on a sound financial footing."
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