NEW YORK Small companies are finding ways to get cash without going to the bank. For any company, the amount of money flowing in or out is critical to its success. When money is tight, paying basic bills such as rent and electricity can get dicey.

Here are a few ways some small businesses are keeping the cash spigot flowing.

Joe Reini needed to borrow money in 2009 because cash flow at his Atlanta-based engineering services company, Mason-Grey Corp., was starting to suffer. Several clients had pulled out of planned projects they could no longer afford. He had no luck trying to get a loan. He was even turned down by a bank that he had a done business with for eight years.

So Reini turned to an online service called the Receivables Exchange, which runs a market for receivables – the money that a business is owed from customers after it sells a product or service.

Here’s how it works: Company A is owed $1,000 by Company B. Company A posts its invoice on the Receivables Exchange, where investors can bid for it – for an amount below face value. Company A chooses among the bidders and gets the cash it needs, sometimes within a day. When Company B pays the invoice, the Receivables Exchange handles the transaction and collects a commission.

If Company B doesn’t pay, then Company A would have to pay back the investor. But Nicolas Perkin, the president of the Receivables Exchange, says companies tend to sell invoices from their customers that have a solid payment history. That reduces the risk. Selling invoices allowed Mason-Grey to improve its cash flow, and it was able to hire 20 more staffers. Reini says the company’s revenue has doubled since late 2008.

Part of managing cash flow is knowing when a bill will be paid. That’s where companies such as Ariba help. Ariba offers a service called Dynamic Discounting that allows buyers and sellers to negotiate payment terms online. The supplier uses Dynamic Discounting to get a commitment for a payment date from the customer, which eliminates the uncertainty of when a check might arrive in the mail. The service also allows companies to get money sooner by offering an early payment discount. So if a company needs cash now, it can negotiate with its customers online and get paid through Dynamic Discounting.

Mediafly, a Chicago-based firm that helps companies get marketing videos and other content onto mobile devices, is six years old, too young to get a loan or line of credit from a bank, says Chief Financial Officer Johnathan Evarts. “When you don’t know when the money is coming, you can’t hire staff as quickly as you’d like,” he says. With Dynamic Discounting, “we know the day we’re going to get paid.”

Stretching it out

Sometimes having healthy cash flow means holding onto the cash that’s coming in for a longer time – or not having that cash leave a company’s coffers as fast. One way to make that happen is to ask suppliers to extend payment terms.

Mark Toolan, a certified public accountant in Exton, Pa., says his clients have been asking for installment payment plans for the last two years.

“I probably have got more people on payment plans than I ever have since I’ve been in business,” says Toolan, who founded his business in 1997.

Toolan is more lenient because he wants to preserve his relationship with his clients. “In difficult times, you’re not going to just terminate the relationship. We’re going to work with them.”

Dun & Bradstreet Credibility Corp., a service that rates the creditworthiness of businesses, has seen an increase in the use of more lenient payment terms – what’s called trade credit – by small companies since the end of the recession. CEO Jeff Stibel says the volume of trade credit has risen by 10 percent to 12 percent since late 2010.

Trade credit is a decades-old practice. Suppliers agree to payment terms of 30, 45, 60 or 90 days and don’t charge interest. The terms depend on the customer’s credit history and the relationship between the companies. Many suppliers give discounts to customers who pay early.