How do you pay the bills when the party’s over and the guests have gone?

Democratic National Convention organizers are about to find out.

After struggling for more than a year to raise money – and ultimately coming up short – they face $10 million in debts and unpaid obligations, according to reports filed this week with the Federal Election Commission.

“This is a difficult debt to retire,” said Viveca Novak, a spokeswoman for the Center for Responsive Politics. “If (President) Obama loses on Nov. 6, then very few people are going to want to give to this lingering debt from the convention.”

The Charlotte host committee raised $24.1 million, short of their revised goal of $31.1 million. The original target was $36.6 million.

Restrictions imposed by the White House barred the committee from raising corporate money or individual donations above $100,000.

A separate fund, called New American City, was under no such restrictions. It took corporate money in raising about $20 million in cash and loans. That fund was intended to pay mainly for welcome events, though $5 million went to use Time Warner Cable Arena.

The reports show an unpaid loan of $7.9 million against a line of credit guaranteed by Duke Energy Corp.

The host committee also listed debts of $1.8 million. New American City had obligations of $270,000.

“The host committee is bound … to meet needs necessary for a successful convention,” Tracy Russ, the committee’s chief marketing officer, said in a statement. “The … committee continues to receive donations based on commitments made in support of this convention, and efforts to meet obligations continue.”

But it’s unclear how the debts will be paid, and whether corporate money will be used.

Neither Mayor Anthony Foxx nor Duke CEO Jim Rogers, the committee co-chairs, were available for comment. Neither was Dan Murrey, the committee’s executive director. Joe Sandler, its Washington attorney, did not respond to emails.

Murrey had said Wednesday that neither the Obama campaign nor the Democratic National Committee will help make up the shortfall.

“I have no idea what they’re going to do to get that (debt) cleared,” said Mark Erwin, a Charlotte investor and host committee member. “This whole thing is new because in the past, the White House didn’t come down with that edict (restricting contributions). That didn’t work out so well.”

Aside from the bank debt, the biggest outstanding obligation is to Maryland-based Hargrove Inc., the convention’s exposition and event services provider. It’s owed $972,702.

A spokeswoman said the company doesn’t discuss financial matters. “We have no concerns about getting paid,” said Brent Dannen, studio manager of Centerstaging, a California company that provided musical production.

Also on the list of creditors: the city of Charlotte.

The host committee owes the city $133,000 for convention center operations and $28,000 for volunteer shuttles. In the past, city officials have said taxpayers will not be on the hook for any convention expenses.

“I’m not worried at all,” said Carol Jennings, the city’s liaison to the convention. She said bills are still being processed. “They’re being very responsive,” she said of the host committee.

A Duke spokesman has said the company would not use any ratepayer funds to pay for the convention.

Novak, of the Center for Responsive Politics, said the committee’s self-imposed restrictions would make it harder to raise the money.

“They made it complicated and difficult for themselves in an effort to not take huge contributions from fat cats or corporations,” she said. “But this is the price they’re paying.”