Mistakes happen, even though much of our financial world is now automated. Billing errors can occur, and when they do, correcting them can be frustrating.

You may get a bill for something you didn’t buy, a purchase you didn’t make shows up on your credit card statement, or a hospital mistakes you for someone with a similar name. Some of these mistakes are honest errors, while others may be an alert that fraud has occurred.

Common types of errors include:

• Being charged for a product you didn’t buy or a service you didn’t receive.

• Being charged full price for a product or service you purchased at a discount.

• Getting billed twice for the same product or service.

• Being charged for the wrong product or service from a vendor or merchant you did business with.

When you discover a mistake, act quickly. The sooner you alert the service provider or merchant of the error, the faster they can act to help you resolve the problem. The first step is to be vigilant for errors.

When you buy something on sale – either in a store or online – pay close attention to the actual price, and recheck that figure at check out. If the figure is wrong, immediately alert the cashier for in-store purchases, and don’t click the “finalize purchase” button online until you’ve checked out the discrepancy.

For errors on credit card statements, utility bills, medical provider bills and others, you’ll need to investigate the source of the error. Credit card companies will generally allow you to put a short hold on a charge while you (and they) investigate, and you won’t be penalized or charged interest during that grace period. Just be sure you know when that time is up and when charges may begin to accrue.

Dealing effectively with a billing error almost always involves talking with a person, so be sure to keep good notes on who you talk to, when discussions occur and the specific details of the conversation. If the merchant or service provider offers online chat, save a transcript of the conversation.

It’s also a good idea to familiarize yourself with the federal Fair Debt Collection Practices Act, which governs how creditors must deal with you when pursuing you for an outstanding debt.

Catching errors early on will help you stay on top of things before they become a bigger issue. Products such as freecreditscore.com allow you to keep an eye on your credit, so if something does slip through the cracks and land on your credit report, you can follow up quickly.