The way a couple manage their money can make or break a relationship. Is there a magic formula, asks Fionola Meredith

One way to gauge the balance of power between a married or co-habiting couple is to ask who cleans the toilet. If one partner regularly spends time dutifully wielding the loo brush and bleach, it can provide a real clue into who wears the trousers in that particular relationship.

But a far more accurate insight into the murky world of marital power relations can be gleaned from looking at a couple's finances. The way a couple manage their money isn't just about paying the bills. It's a reliable diagnostic of the fault-lines in a relationship - and a useful measure of the extent to which old gender stereotypes still exert their influence.

So when British culture secretary - and minister for women - Tessa Jowell revealed that her (now estranged) husband David Mills paid the mortgage on their home, and that she had blithely signed her name on the mortgage form without asking when it would be paid back, many women reacted with incredulity, seeing it as a surprisingly dizzy admission. From behind the facade of feminist government minister, it appeared that an obedient wifelet was struggling to emerge.

Surely the days of the man as the autocratic managing director of the household coffers are long gone in most relationships? After all, more and more women are financially independent.

Now it's often women who take charge of the family finances, and in an increasing number of cases their income outstrips their partner's.

A recent survey for the US bank PNC, which questioned 1,500 people who earned $150,000 (€123,500) or more and had at least $500,000 in assets to invest, found that women and men can have very different perceptions of how they manage their finances. Two-thirds of women surveyed believed they shared the financial decision-making with their spouses; but less than half of the men agreed that they carved up the decision-making equally. Just 12 per cent of women thought they were in charge. And while more than one in five men said they believed the partner who contributes more income has a greater say in deciding non-financial matters, almost two thirds of women - perhaps mindful of the impact of child-rearing on their financial fire-power - disagreed with that.

Yet a surprising number of women are still willing to cede total control of the cash to their husbands, while they get on with the serious business of raising children. Aisling, a university-educated full-time mother of two young children, says she hasn't a clue about how her businessman partner, Brian, manages the family finances. He simply hands over cash when she needs it. It's only recently that she has got her own credit card, and her partner even pays the monthly bill on her mobile phone.

"It used to bother me," she says, "but not any more. I've seen that he's trustworthy." Aisling thinks their seemingly old-fashioned approach to gender roles is a fair one. "I look after the kids and he looks after the finances. I may not know how much money is coming in and out each month, but Brian doesn't know when the children's vaccinations are due. It's a division that we're both happy to adhere to."

Lisa O'Hara, of the Marriage and Relationship Counselling Service (MRCS) in Dublin, says there is no magic formula when it comes to sorting out financial responsibilities - it's entirely individual to each couple. But she says that problems can arise when children come along.

"Full-time motherhood is a very important role, but it's rarely socially valued. When a mother is used to earning a wage, then makes the decision to become a stay-at-home mum, she has to get used to living without that income. It's vital that she recognises the value of staying at home with the baby, and that she derives her level of satisfaction not from her direct earning capacity - or lack of it - but from the role that she's playing. And it's also about not looking at her partner's full-time wage as only his."

THE NEED TO renegotiate the financial arrangements after the birth of a child is familiar to Loretta and Dave McGillion of Midleton, Co Cork. Loretta runs Lavender Yarns, an online knitting store, on a part-time basis, in addition to looking after their 17-month-old son, Liam. Dave works full-time as a health club manager.

Loretta says, "When we were both working full-time, we saved one income and lived off the other one. It's different now. My business is still at the growing stage - it pays for things like the broadband, and the phone. Though I do think the idea of the husband as breadwinner is an outmoded stereotype - I pay more of the household bills!"

Loretta agrees with Lisa O'Hara's emphasis on the right psychological attitude to the change in work practices. "It's important not to feel like a kept woman - using his money, or being given an allowance. I look at the money now more as 'ours' rather than 'mine' and 'his' - it's a shared resource."

Dave agrees: "There's a lot more equality today and rightly so. We both contribute to the family - and not just financially."

"Money can be one of the biggest stresses in a marriage, so when you're thinking about compatibility, you need to think about a similar attitude to spending and saving," adds Loretta.

It's a pragmatic approach to relationship-building. But it's one that more and more couples are taking. Research conducted by insurance company Prudential has found that money is a key factor in relationships, with many people placing a significant level of importance on money when choosing a partner. Only 16 per cent of those surveyed believed that money was not important in relationships. So it makes sense to schedule in a frank chat about finances before shacking up together.

Relationship psychotherapist Paula Hall says, "If you and your partner have the same attitude towards money, the only thing you need to agree on is who's going to manage the income and expenditure. If your attitudes are quite different, you'll need to agree on some basic budget priorities, such as how much money you'll spend on household essentials and bills, how much on leisure and entertainment, and how much you'll save."

LORETTA IS SCEPTICAL of the old myth that women can't resist frittering away their cash on luxuries such as clothes, cosmetics and holidays. "I know quite a few men who spend much more than women on their appearance."

But Paula Gilmurray, from Lisburn, near Belfast, ruefully admits that she doesn't worry about being in debt. While husband Kieran brings a careful and measured attitude to the finances, Paula takes a more laissez-faire approach.

"If he doesn't have it, he doesn't spend it. But I just use the plastic. I will have a holiday, no matter what the cost. Kieran says that because it's not a necessity, if I want it, I should pay for it. So I just put it on the Visa. Summer holidays and Christmas - that's my credit cycle."

Kieran thinks that his background might have coloured his view of family finances. "We never had money as kids, so now I'm really careful, watching what comes in and out, what needs saved, what doesn't, and making sure the mortgage gets paid."

Relationship experts agree that early experiences, and the values that people are brought up with, have the greatest impact on our approach to money, determining whether we see it as primarily for enjoyment (the "live for today, no pockets in a shroud" attitude) or for security (the "be prepared, save for a rainy day" style).

Some couples with radically differing perspectives on cash fit together in a harmonious yin-and-yang-style accommodation, balancing out each other's excesses. Others find that their wildly divergent "financial personalities" means a lot of shouting and bouts of tug-of-war over the joint credit card on the living-room floor.

On the money

Single accounts

You both stay financially independent

You aren't liable for your partner's debts

If you split up, separating your financial relationship will be

easier

Joint accounts

It's a powerful way of showing your commitment and trust

You both take equal responsibility for your finances

For stay-at-home partners, it's important to regard income as shared