The Fix: Call your mortgage company right away, explain the situation and tell them when you’ll be sending the check; you’ll probably incur a “late” fee, detailed in your mortgage agreement. If you goofed simply because you’re a bit disorganized when it comes to paperwork, consider having your payment automatically withdrawn from your checking account. “Missing a mortgage payment is one of the worst things you can do to your credit,” says Howard S. Dvorkin, founder of the nonprofit Consolidated Credit Counseling Services, Inc. “It can make it difficult to refinance or buy a new home in the future.”

If you’re facing a job loss or medical crisis, and aren’t sure how long you’ll be behind, call the mortgage company’s lenders’ loss mitigation department. They are trained to handle a variety of situations and can help you examine your options. “They really want you to keep your house,” assures Gerri Detweiler, author of The Ultimate Credit Handbook. “They’re not anxious to foreclose on you.”

Mess Up #2: You didn’t file your taxes

The Fix: Even if you’re worried that you can’t pay what you owe, it’s important to file returns as quickly as possible, says Tom Vastardis, a New Jersey-based accountant who regularly helps clients with tax repayment problems. “The IRS folks are not as mean as you think,” he adds. “They’ll work with you to get your taxes paid, or get your refund if you’re owed one.”

If you think you owe less than $10,000, call the IRS directly. (For your local office’s number, go to irs.gov.) A rep will guide you through the filing steps and, if necessary, set up a repayment plan. Suspect you owe more than $10,000? Hire a tax professional; he may be able to negotiate an “offer in compromise,” which could cut your tax bill by as much as half.

Mess Up #3: You maxed out a credit card (or six!)

The Fix: First, stop using the cards immediately. While transferring your outstanding balances to a lower-interest card might temporarily decrease monthly payments, it won’t really help you curb overspending tendencies.

Next, advises Dvorkin, make a list of all your credit card balances and interest rates. Some experts suggest paying off the card with the smallest balance first, since seeing an entire debt disappear provides a psychological boost that can help you stay motivated. But another option is to pay down the card with the highest interest rate first. “That works best for people who are all about the math of debt,” says Dvorkin. “It’s the card that’s really costing you the most.”

For professional help with credit card debt, call the National Foundation for Credit Counseling (nfcc.org) or the Association of Independent Consumer Credit Counseling Agencies (aiccca.org).

Mess Up #4: Your doctor has called a debt collector!

The Fix: Before you do anything, make sure the debt is yours, says Detweiler. If the charge is one you believe your insurance company should have paid, contact your state’s insurance commission for help with dispute resolution.

If the bill is your responsibility, try negotiating with the doctor’s office or hospital that reported it. Offer to pay whatever you can afford — even if it’s as little as $5 a month. “They’ll probably be happy to accept your offer,” says Detweiler. They know they’ll actually get their money eventually, rather than having to wonder how the debt collectors are doing. If it turns out you must deal with a collection agency, negotiate again. “Offer to pay the debt in full, rather than in installments — if you can get the collector’s word in writing that they won’t disclose the debt to credit-reporting organizations.”

Mess Up #5: You bounced a check

The Fix: Visit your bank right away. If this was a onetime mishap, they may waive the insufficient funds fee (which usually runs around $25 per check). Then call the business or individual who didn’t get paid. They will probably insist you send them a certified check or money order — and, again, don’t delay.

“Bouncing a check or not having money in your account to cover a debit card transaction can be considered fraud,” says Dvorkin. Then set up your bank account so that in the future, you’re guaranteed overdraft protection.