Deal, or no deal?

But Ronkin was leery. First of all, the offer came from online lender Quicken Loans, and she was skeptical of any deal that originated on the Internet. And Quicken wanted a steep 3 points on the loan, which worked out to $9,000.

But her client was smitten with the Cambridge condo, in a two-family near Inman Square. She considered the numbers, had lengthy conversations with a Quicken representative, and decided to press ahead. Days before the loan was scheduled to close last month, the company said it had misclassified the property as a single-family. Under new underwriting rules taking hold in the industry, condos required a bigger down payment; to close the deal, the company said she needed to have more money up front.

In the end the client choose to stay with the loan and cashed in stock to get her down payment to 10 percent.

The client declined to discuss her situation, but Ronkin said she was frustrated at how her client was treated.

Aaron Emerson, a Quicken Loans spokesman, said the company found it “regrettable that information about this transaction is coming from a third party who was not privy to the discussions regarding this mortgage. Our client was client treated fairly throughout the process. It is unfortunate that someone with less than a full understanding of the situation is speaking on behalf of our client.’’

The mortgage industry has changed considerably in the last year. If you have anything less than a 20 percent down payment and stellar credit, expect to work hard to become qualified and be prepared to have to pay more in certain circumstances, in fees or in higher rates, and sometimes both. The tougher standards are the lending industry’s reaction to the subprime mortgage debacle, when many were stuck with money-losing loans made in the days of easy money.

Interest rates are as low as they have been in years. The average 30-year fixed-rate mortgage is hovering around 5 percent, down more than a percentage point from a year ago. And 15-year and adjustable-rate mortgages can be had for as low as 4.5 percent.

But to take advantage of solid offers - without hidden costs - borrowers should have good credit and bullet-proof documentation of their incomes. “Banks want to make sure you have a job, and they want you to prove it,’’ said Karen Glaser, president of the Mortgage Place in Sharon.

More than ever, the entryway to a good mortgage is a good credit score. To get anywhere near those touted 5 percent interest rates, lenders say you need a score of 720 or higher, on the 850-point FICO scale. And small changes in the score, from 740 to 760 points, for example, could mean as much as a half-percentage point difference in the loan rate.

While there is no magic bullet to boost one’s credit score, there are basic steps prospective borrowers should begin taking as early as possible in the home-buying process: pay your bills on time and pay down your credit card balances, if not in full, then to less than half of card’s credit limit.

Credit experts caution against quick fixes, like eliminating all your unused credit cards. Suddenly opening new accounts to be build more credit is also likely to be counter-productive - that will trigger more credit inquiries, which can look bad on your report. What helps is having several long-term revolving accounts in good standing.

Borrowers must review their credit report for errors (the three main credit reporting agencies provide one free report per calendar year). The agencies - Equifax, Experian, and TransUnion - must investigate a disputed item within 30 days of receiving a written request. More information on how to deal with the credit agencies can be found at the website of the state attorney general’s office (www.mass.gov/ag).

For documenting income and assets, borrowers need to assemble W-2 tax forms, bank statements, and pay stubs. In addition, lenders may also require a Form 4506, authorizing the IRS to disclose tax returns.

“It’s new world out there,’’ said Jim Driscoll, a manager at the Danvers office of Mortgage Master. “The market went from one end of the spectrum to the other, where lending is very tight, and even clients that qualify are really getting looked at under the microscope.’’

In one recent case, Driscoll recalls the ripple effect that one missing form created. The lender on one transaction did not have the borrower’s IRS authorization form. That purchase was delayed. The sellers, in turn, could not close on the home they were buying; and their sellers, too, could not then complete their plans to buy a new home.

“It was like three dominoes falling,’’ he said.

A good credit score and a good job will only get you so far if you do not have a 20 percent down payment. And for those with less than 20 percent, getting private mortgage insurance, generally a requirement for such loans, is harder these days, too.

For decades, those who could not afford a substantial down payment could rely on the Federal Housing Administration, which makes loans with a low down payment, now 3.5 percent, and tacks on a slight premiums for insurance.

But FHA loans are not always good fit. In the case of condos, they are limited to buildings with four or more units, which excludes a fixture of the Boston market, the triple- decker. Moreover, there are a slew of restrictions for newer condo buildings, requiring, for example, that a majority of units to be pre-sold to owner-occupants.

And these will be getting more stringent on Oct. 1, making it impossible for individual buyers to get “spot approval’’ when a building doesn’t qualify for FHA financing, and setting reserve fund requirements for condo associations.

An alternative is the state agency MassHousing, which has programs that require less than a 5 percent down payment, with limited mortgage insurance fees. And borrowers can use the federal $8,000 home buyer tax credit toward their down payment or closing costs - at least until Nov. 30.

Both MassHousing and FHA loans have income limits. At MassHousing, for example, household income cannot exceed $113,800, or $67,400 to also get mortgage insurance subsidies.

Getting financing can be even more vexing at the higher end of the market. While the cap on mortgages backed by Fannie Mae and Freddie Mac was recently raised from $417,000 to $523,750 for some parts of greater Boston, there are still many buyers who need more than that, and so are reliant on jumbo loans. Those are hard to get with anything less than a 20 to 25 percent down payment.

In recent months, brokers and lenders report at least one encouraging development - community-based banks are offering more attractive terms for jumbos. But Sean Riley, the chief executive of Mortgage Equity Partners in Lynnfield, said their involvement remains limited.

“They’re taking the cream of the crop. Typically with jumbo loans, they’ve got a finite portfolio,’’ he said.