Of the Bankrate survey participants who were married or living with their partner, 77 percent said they have at least one joint account.
Keep an eye out for worrisome behavior that may emerge once you're living together and sharing your finances.
"Whether they pay bills on time or whether they move a credit card balance from one place to another to keep debt collectors at bay," said Cetera.
Once you and your partner become serious enough to discuss your joint finances, prepare for an open discussion of your credit card histories and more.
Consider these five steps to ensure that chat runs smoothly:
Go on a date — to talk about money: "A relaxing Sunday morning is a more ideal time to have a financial conversation than at the end of a long workday when you're lying in bed and exhausted," said Alexa von Tobel, founder and CEO of LearnVest.
Stay casual: Your "finance date" shouldn't be a formal affair. You can have your talk over a glass of wine and some takeout. Just make sure that you're having this chat in a quiet place.
Be prepared: Do your homework before you meet up. Bring your credit card and bank statements, student and car loan balances, or a copy of your credit score and relevant reports. "It's important to come to the conversation with full knowledge of your financial picture," said von Tobel.
Discuss combining accounts: Blending your finances with your squeeze might not be the best idea for you two—or it might be.
"If you love compromise, combining your finances may be a good fit," said von Tobel. "If you're fiercely independent, keeping your finances separate may be the way to go."
Keep your common goals in mind: Wrap up your "finance date" with a round-up of your shared goals, even if they're long term.