Should you know your partner's credit score? An expert weighs in

Money is often cited as one of the biggest sources of conflicts for couples, which is why building a financial bond with your partner is so important. And that includes disclosing your credit score — good or bad.

When it comes to discussing your credit history, it's better for both people in a relationship to be an open book.

Below, CNBC Select asked Rod Griffin, Experian's senior director of consumer education and advocacy, for his advice on why you should know your partner's credit score.

1. Why you should know your partner's credit score
2. How soon do you have the credit conversation?
3. What if my partner doesn't want to share their credit score?
4. What if my partner has a low credit score?
5. Does your partner's bad credit affect you?
6. Is there a 'red flag credit score number' to look out for?

It's good to know your partner's credit score — and even more important to know their complete credit history, especially if you're in a long-term relationship or a committed relationship.

If ever down the line you and your partner would want to enter into any sort of joint agreement, such as opening a joint credit card, both of your credit histories and credit scores will play a big factor. And if one of you has issues with your credit history or a less than optimal credit score, it's better to know sooner than later.

"It gives you the knowledge that you need to work together to improve, so that you can achieve your shared goals," Griffin says. "Really knowing about your partner's credit score, knowing about their credit history, helps you work together in setting financial goals and working toward them."

"I sometimes jokingly say that instead of the pickup line being, 'What's your sign?' it should be, 'What's your score?'" Griffin says.

While the first time you meet someone may be a bit too soon to ask about their credit score, there is some value in knowing each other's financial habits early on.

If you just started dating but are moving toward a committed relationship, it's important to understand each other's approaches to money and money styles.

In more extreme cases, there are the red flags to watch out for that might deserve more attention.

"If you are with someone, and you are suspicious of how they are spending money — meaning they seem to be spending a lot more than they, based on what you know about them, should have to spend — that may be a time to start talking about money."

Early on, try getting comfortable talking about money in more general terms; it doesn't have to entail asking each other's credit score right away.

"Talking about what you want to achieve financially with someone and saying, 'I want to, at some point, own a house, what do you think of that goal? What are your financial goals?'" Griffin says.

Then, move toward talking about credit as you and your partner think about getting more serious. Discuss where you two are financially and make sure you're setting goals together.

All signs point to it being healthy to know your partner's credit score, but he or she may not want to reveal it. The way people manage money can get very subjective and personal, so be sensitive to that.

That said, "In my experience, if you are not comfortable sharing your credit history or your credit score, that's a cause for concern," Griffin says. "If you are unwilling to share information about your credit history, your partner's probably going to wonder why, and it might create tension right away."

Though money is traditionally the most common reason for problems in relationships, more often it's money secrets or hiding things about money that is at the root of it. Being open about your financial situation can help you work together on addressing any issues you have and seeing differences in the way you manage money.

While it can be concerning if you find out that your potential partner has a terrible credit score, it doesn't mean you should end the relationship because of it. See it as an indicator to ask more questions and look at what has happened to make their credit score drop.

"Life happens, and so there may be a perfectly valid reason that their score has suffered a bit or isn't very strong," Griffin says. "But you can work together to improve it. If you approach things from that goal perspective, it might be a positive for you as a couple."

Try having the person with the lower credit score become an authorized user on the other's account to help boost their own score, and if that isn't an option, there are a few cards that are marketed toward people with less-than-stellar credit histories.

Secured cards are typically the best choice for people with bad credit. These cards require a security deposit (often $200) that becomes your line of credit. When you use your secured card responsibly — paying your bill on time and in full each month — you can begin to improve your credit score.

The Discover it® Secured Credit Card is a well-rounded secured card that offers many of the benefits that are typically found with unsecured cards. Cardholders can earn cash back, receive a generous cashback match after their first year (for new card members in the first year only), use the card overseas without incurring added fees and more — all for no annual fee.

Everyone always has their own credit history and their own credit score. Even when you get married, your credit reports are not merged.

Credit scores become an issue when you and your partner are applying for a joint account, such as when you are planning to buy a house. If your partner has a poor credit score, it can make it more difficult for you to jointly qualify, or you may potentially have to pay much higher interest rates.

Other joint applications, such as a combined credit card, can be at risk of not being approved as well, including if you're going to have credit cards together or if you're going to merge your credit card accounts. "Credit scores are an indicator of how a person manages their debts," Griffin says. "If you merge them, that could affect your partner's credit history as well."

You may want to hold off on merging anything or filling out a joint application until the partner with the bad credit works their way up to good or excellent credit. They then may qualify for cards with generous welcome bonus offers and robust rewards programs, such as the American Express® Gold Card and the Chase Sapphire Reserve®, two of CNBC Select's top-rated rewards cards. Terms apply.

Considering credit score ranges vary based on the credit scoring model used (FICO versus VantageScore) and the credit bureau (Experian, Equifax and TransUnion) that pulls the score, you have to be careful when sharing and comparing credit scores with your partner. Make sure you are both looking at and understanding the same model.

Griffin says there isn't any one specific credit score number to be afraid of because everyone is different. If your partner has been divorced, they might have had to go through bankruptcy as a result and now has a poor score, but for a very valid reason. "And that happens most often to women, unfortunately, so that's something to consider," he says.

"It's not just what is their number, but it's why is that number what it is," Griffin says. "It's important to understand that because there are always paths to improvement."

When it comes to talking money with your significant other, it's worth it in the long run to start these tough conversations early. Ease into it by asking questions about how your partner views money, their spending habits and how they were raised to think about money. This can help lead the way to asking their credit score and history that, soon enough, will suit both of you to know.

"I think another keyword in our conversations is 'partner,' and if you're a partner it means you share with one another," Griffin says. "If you're not sharing equally, you're not a partner. That's critical and that goes to money conversations as well as other parts of life."

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