Our website describes the various aspects of using credit cards and everything that is related to the credit card numbers, and the Luhn algorithm has a direct connection with it. **In this article of ours, we will uncover what is the Luhn algorithm, what are its features, and how to use it**. The algorithm is explained in a simple language, so you don’t have to worry that you may not understand something. Besides, you will get clear instructions on how to check a credit card number with the help of the Luhn algorithm. Enjoy the read!

**The Basics of the Luhn Algorithm**

The Luhn algorithm is also known as the mod 10 algorithm or the modulus 10 algorithm. This algorithm appears to be a pretty simple formula for validating the numbers of credit cards. When you type your credit card number on an online website and make a mistake, you get to see an error, which means that the system knows that there has been made a mistake in the card number. The system knows that exactly thanks to the Luhn algorithm, which helps to define it.

Initially, the Luhn algorithm was created by Hans Peter Luhn, who worked at IBM as a scientist at the time of the formula’s creation. In 1954, **he filed a patent for this formula and received the patent in 1960**. As of the present time, this mod 10 algorithm appears to be in the public domain, which also allows to be in a wide use across the globe.

But the modulus 10 algorithm is used not only for validating the credit card numbers. This simple formula is also used for validating the numbers of IMEI numbers, Social Security Numbers of Canada, the number of the National Provider Identified in the United States, and the Social Security Numbers in Greece (AMKA). As you can see, this formula is quite useful and appears to be in quite a wide use nowadays.

Many users wrongly think that this mod 10 algorithm is intended to be a means of protecting from malicious attacks. However, one should understand that the Luhn algorithm is simply a formula that helps to identify accidental errors, such as mistyping a credit card number on some website. Therefore, **this modulus 10 algorithm has nothing to do with protecting any data** – it just appears to be a means of verifying codes. And, of course, the most used way of this mod 10 algorithm is identifying the mistyping errors of credit card numbers.

As a matter of fact, our website also utilizes several tools that function on the basis of the mod 10 formula, and you can even make use and take advantage of them. The first tool we recommend you to utilize and that you can find on our website is the **Credit Card Generator** tool. What does this tool allow you to do? By utilizing the mod 10 algorithm, this tool creates fake numbers of credit cards that look totally valid and normal. Then, you can use those credit card numbers on the websites that require you to provide your card number. With the help of that tool, you can create fake credit card numbers of such cards like JCB, Diners, Discover, AmEx, MasterCard, and Visa.

On the other hand, you can also make use of another useful tool, which is available on our website. It is going about the **Credit Card Checker** tool. By using the Luhn algorithm, this tool actually validates the credit card number that you will enter. Once you have entered a credit card number, you can click on “OK” and you will get to see whether this credit card number is valid. Additionally, you will also get to see the examples of various credit card numbers, including the numbers of such credit cards like Visa, MasterCard, JCB, Discover, Diners Club, and American Express.

**How to Use the Luhn Algorithm**

As it was already said above, the mod 10 algorithm is applied by various systems to check errors and validate numbers. Since this algorithm appears to be quite a simple formula, it can be used not only by various systems and machines, but even you can check a credit card number on your own.

For instance, **this article** on our website explores what are the main constituents of any credit card number. By knowing the structure of a credit card number, you will be able to break it up and understand whether it is valid. In short, any credit card number includes the major industry identifier (the first digit that identifies a company), the issuer identification number (the first 6 digits that identify a bank that has issued a credit card), and the account identifier of a customer (the remaining digits except of the last one).

By knowing that simple structure and utilizing the Luhn algorithm, you will be able to validate your credit card number on your own. For instance, **you should make the following steps in order to check a 16-digit long credit card number**:

- Every other digit in the card number should be doubled and noted down (start with the first digit).
- Then, you should transform the double digits you received (for instance, 6*2=12) into one-digit results. In the given example, it would be like this: 1+2=3.
- Add up all the digits that you doubled (including the ones that you transformed from two-digit results into one-digit results).
- Then, get back to the initial credit card number. Add up all the numbers that you ignored during the first phase (including the last digit).
- Eventually, add those two sums that you have received. If you got a zero, then your credit card number is valid.

But what one should do with 15-digit long credit card numbers (the cards from American Express, for example, feature such numbers)? Actually, you have to change only one thing: you need to start doubling with the second digit. Regarding everything else, the instructions are the same. The Luhn algorithm appears to be that simple, and, as you can observe, you can easily apply this algorithm on your own.

**The Luhn Algorithm Today**

The Luhn algorithm was quite an important discovery of its time and nowadays it is still widely used, but there are large portions of criticisms regarding the use of this formula. As it was said above, this is a simple formula and it cannot prevent malicious actions – all it can do is identifying errors, and this is something that must be kept in mind. And while people may seem that this is important, it’s a wrong way to point to this.

The Luhn algorithm has serious drawbacks in regards to its main aim – spotting errors in the code numbers. **While this mod 10 algorithm will detect any single digit error, it may be difficult to apply it to more complex computations**. For instance, the Luhn algorithm would be unable to detect the transposition of any two-digit sequence starting from 09 and ending with 90. In addition to that, this algorithm can detect only 7 out of 10 possible twin errors. In a result, this formula has a far bigger number of vulnerabilities than, for example, the Damm algorithm and the Verhoeff algorithm, which tend to be far more complex.

To sum up, it can be said that the Luhn algorithm today appears to be one of the easiest way to validate credit card numbers. Our website also utilizes a number of tools that are based on this formula. Considering that this tends to be the easiest way to validate the numbers of such documents like credit cards, IMEI, or some Social Security Numbers, this formula will be in use for a long time. At least, it seems so for now. After all, it’s thanks to this formula we see an error when mistyping a credit card number.

In addition to that, our website also features such a section like **Credit Cards**. There, you can find reviews of the best and most beneficial credit cards on the market. For instance, the **Citibank Credit Card Review** contains insightful information about the top credit cards from Citi. Likewise, you can also get to know more about credit cards by reading the **Chase Credit Card Review**, **Amazon Credit Card Review**, or **Best Buy Credit Card Review**.