Readers should note: The data and information in the article are compiled from general market sources and do not apply specifically to SeABank's products or services.

1. What is a credit card number?

A credit card number is a series of numbers embossed on it front of the card, usually includes 16 digits. Each credit card will have a unique card number, like an "identity card" of the card, helping to distinguish your card from other cards.

Credit card number location: The series of numbers located on the front of the credit card.
Card structure: Credit card codes in Vietnam include 16 digits, each digit or string of digits has different meanings.

A credit card number is a 16-digit number embossed on the back of the credit card.

2. Structure of credit card number

Understanding the structure of a credit card number will help you understand the meaning of the type of card you own.

Structure of credit card numbers

First digit: Tells you information about the card-issuing bank.
Next 3-digit cluster: Shows the ID code of the organization or bank.
The next set of 9 digits: Cardholder's account number at the bank.
Last digit: This is a random digit according to the Luhn algorithm and is used to check the accuracy of the credit card. This digit is also known as checksum.

Regulations on credit card issuers are as follows:

Digits 1, 2: credit cards issued by airlines;
Digit 3: entertainment, tourism and travel agencies;
Digits 4 - 5: financial institutions and banks;
Digit 6: banks and businesses;
Digit 7: oil and gas company;
Digit 8: telecommunications company;
Digit 9: credit card issued by the State.

How to check the validity of a credit card number

The last digit of the credit card number sequence will be used to check the validity of the card number through the Luhn algorithm. For example: with card number 9605 1722 8932 7511 - 4360 1278 2676 6868

Step 1: Keep the numbers in odd positions 1 - 3 - 5... (count from right to left), take the numbers in even positions 2 - 4 - 6... We have: (8) 3 (12) 0 (2) 2 (14) 8 (4) 6 (14) 6 (12) 8 (12) 8
Step 2: Double the numbers you just got and replace them with even numbers. At this point, the number sequence has the following form: (16) 3 (24) 0 (4) 2 (28) 8 (8) 6 (28) 6 (24) 8 (24) 8. If the multiplication result has two digits, add the two digits together. The new number sequence is: (7) 3 (6) 0 (4) 2 (1) 8 (8) 6 (1) 6 (8) 8 (6) 8
Step 3: Add the digits in the newly found number sequence together. If the total is divisible by 10, the credit card number is considered valid: 7 + 3 + 6 + 0 + 4 + 2 + 1 + 8 + 8 + 6 + 1 + 6 + 6 + 8 + 6 + 8 = 72 is not divisible by 10, so this credit card number will not be valid.

3. Function of credit card number

Credit card numbers have many different functions such as:

Quickly look up credit card balance: You provide the bank with your credit card number (last 4 digits), along with some other personal information to verify your identity. The bank will provide you with information about the card's available balance.
Transfer money to credit card: You need to enter the exact credit card number to transfer money to the card. You can do it through ATMs, Internet Banking, Mobile Banking.
Used to look up limits: Limit is the maximum amount of money you are allowed to spend with a credit card in a certain period of time. You can look up the card limit by credit card number and do so by contacting the bank or through online transaction channels.
Used to change pin code: With your credit card number, you can easily change your PIN at the bank at an ATM or Internet banking or Mobile banking.

4. 7 ways to secure credit card numbers

With so many important functions, securing credit card numbers is essential. Here are ways to help you secure your credit cards better:

Absolutely do not lend your credit card to others: When you lend your card to someone else, you are giving them access to your account. They can take advantage of it to make illegal purchases, causing damage to your finances.
Check transaction information on the invoice: Before signing the payment confirmation, you need to carefully check the invoice to detect errors in the payment process, avoiding overcharging or undercharging.
Cover, obscure or remove the CVV/CVC security code on the back of the credit card: CVV/CVC code is a series of security numbers, often required when making online transactions. If this code is leaked, thieves can take advantage of it to make online purchases without needing a physical card. You can use tape to cover the CVV/CVC code when not in use.
Sign the back of the credit card: Your signature is a form of identity authentication when making transactions. Signing the back of the card helps prevent unauthorized use of the card. Because when making transactions, units will compare the signatures on the invoice and the back of the card.
Make sure to always be present when handing over your credit card to the employee who swipes the POS machine. Because when you are not present, others can take advantage of it to swipe the card multiple times or remember card information for later use.
Absolutely do not share credit card information: Credit card information including card number, CVV/CVC code, expiration date... is important information. If exposed, thieves can easily copy the card or make unauthorized online transactions.
Use the OTP security function when paying online: OTP is a one-time authentication code sent to your phone. Using OTP helps increase security for online transactions. When making online payment, you will receive an OTP code via SMS or banking application. You need to enter this code to confirm the transaction.

When using a credit card, you need to keep your card information very secure to avoid illegal appropriation of money.

5. Answer questions about credit card numbers

Let's answer some questions about credit card numbers with SeABank to help you better understand card information. Specifically:

Is it okay to reveal your credit card number?

Reply: Revealing a credit card number, even if it's just a piece of information, is enough for thieves to take advantage of it to make illegal online transactions. Just need the card number, expiration date and CVV/CVC code (the last 3 numbers on the digit strip on the back of the card), thieves can completely buy online and transfer money without needing a physical card.

What should I do if my credit card number is leaked?

Reply: Here's what you should do when your credit card is leaked:

Lock your card immediately: Contact your bank to block your card temporarily or permanently.
Notify the bank: Report the incident to the bank for support in processing and investigation.
Change password: Change the password of the bank account linked to the card to ensure safety.
Check transaction: Carefully check the transaction history to detect unusual transactions and ask the bank to cancel.

How old do you have to be to use a credit card?

Reply: Normally, customers must be 18 years or older to be issued a credit card. However, some banks may allow people under 18 years old to use a secondary credit card through a primary credit card from a relative.

Is a credit card number the same as a bank account number?

Reply: Credit card number and bank account number are two different pieces of information.

Credit card number: Is a unique series of numbers to identify the card, similar to your ID card number.
Bank account number: A number to identify your account at the bank.

How to change credit card number?

Reply: A credit card number is issued once and is tied to your account. Changing a credit card number is not simple and takes a lot of time. You should go directly to the bank for specific advice. Normally, you will have to go through the procedure to re-issue a new card and may have to pay a certain fee.

What should I do if I lose my credit card?

Reply: Call the bank's hotline to block the card. Go to the nearest bank branch to complete procedures to report lost card and request a new card. Change the password of the bank account linked to the card to ensure safety.

Which bank should I get a credit card from?

Reply: Choose a reputable bank with many incentives for using cards. One of the banks that many customers choose to open credit cards today is SeABank - one of the largest joint stock commercial banks in Vietnam.

SeABank is deploying many types of credit cards with many attractive incentives to suit all customers. Great incentives when using SeABank credit cards include:

Interest-free period is up to 55 days.
First year annual fee refund for cardholders who make at least 2 successful transactions and have a total transaction of at least 500,000 VND within the first 30 days since the card was activated.
Installments from 0% for all transactions from 3,000,000 VND or more.
Discount when purchasing on Shopee.
Many attractive offers specific to each type of card.

Countless attractive incentives when opening a credit card at SeABank.

Hope the above article has helped you understand better credit card number as well as the function and meaning of this special number sequence. In particular, you should keep your card information very secure and use the card effectively and profitably with attractive incentives from the bank.

If you want to learn more about SeABank's credit card products, you can contact the nearest transaction points or call Hotline 1900 555 587 or visit the website. www.seabank.com.vn for more detailed information.