Shopping on line can be easy, simple and save you lots of money. It can also take a lot of your time, frustrate you, and result in unwanted purchases. Now the same can be said for regular high street shopping, but with the vast opportunity presented by the Internet it will pay you to spend a few minutes reading this and understanding how to better optimize your Iso 7812 shopping experience:

1. Compare - without doubt the biggest advantage that the Iso 7812 offers shoppers today is the ability to compare thousands of Iso 7812 at a time. This is a great thing, but not necessarily all the time! Too much can be daunting at times so take advantage of the great comparison sites and where possible let them do the hard work for you.

2. Research - if it has been said it will be on the internet. Ignorance is no longer a justifiable reason for buying the wrong thing. Take the time to research in detail everything that you could possible want to know about

3. Testimonials - don't know anybody that has bought a Iso 7812? Wrong! If the Iso 7812 is good the internet will let you know. Use the Internet as a friend and get testimonials before you buy.

4. Questions - Got a question about Iso 7812 then search the Forums, FAQ's, Blogs etc. Don't be afraid to ask .....

5. Reputation - Never heard of the company selling Iso 7812? Don't worry, no reason why you should know every company in the world, but you know someone that does! Use the internet to find out what people are saying about Iso 7812 and build up a picture of their reputation for sales, returns, customer service, delivery etc.

6. Returns - still worried that even after all of the above your Iso 7812 wont be what you want? Check out the returns policy. There is so much competition now that someone, somewhere is bound to offer the terms that you are comfortable with.

7. Feedback - happy with your Iso 7812 then let people know, after all you are depending on others people input in your buying decision, so why not give a little back.

8. Security - check for the yellow padlock on the Iso 7812 site before you buy, and the s after http:/ /i.e. https:// = a secure site

9. Contact - got a question about Iso 7812, or want to leave a comment then check out the sites contact page. Reputable companies have them and respond.

10. Payment - ready to pay for your Iso 7812, then use your credit card or PayPal! Be aware of companies that don't accept them, there may be genuine reasons but given the huge amount of choice you have when buying online there is no reason at all not to buy via credit card or PayPal.

ISO 7812, first published by the International Organization for Standardization (ISO) in 1989, is the international standard governing magnetic stripe identification cards, such as door entry cards, automated teller machine (ATM) cards, and credit cards. Credit card numbers are in fact ISO 7812 numbers. The maximum length of such a number is 19 numerical digits.

A ISO 7812 contains a single-digit major industry identifier (MII), a six-digit issuer identifier number (IIN), an account number, and a single digit checksum. The major industry identifier is considered to be part of the issuer identifier number.

Major industry identifier The major industry identifier (MII) is the first digit of the ISO 7812 number. It identifies the industry within which the card is to be used.

{| class="wikitable"|-----! MII Digit Value! Issuer Category|-----| 0 || ISO/TC 68 and other industry assignments|-----| 1 || Airlines|-----| 2 || Airlines and other industry assignments|-----| 3 || Travel and entertainment|-----| 4 || Banking and financial|-----| 5 || Banking and financial|-----| 6 || Merchandizing and banking|-----| 7 || Petroleum|-----| 8 || Telecommunications and other industry assignments|-----| 9 || National assignment|}

If the major industry identifier is 9 the next three digits are the numeric-3 country code from ISO 3166-1.

Issuer Identifier Number The first six digits, including the major industry identifier, compose the issuer identifier number (IIN). This identifies the issuing organisation. The American Bankers Association is the registration authority for IINs. The official ISO registry of IINs, the "ISO Register of Card Issuer Identification Numbers", is not available to the general public. It is only available to institutitions which hold IINs, issue plastic cards, or act as a financial network or processor. Institutions in the third category must sign a license agreement before they are given access to the registry. Several IINs are well known, especially those representing Credit_card_number#Credit_card_numbering.

Donald E. Eastlake wrote a series of Internet Drafts—the final of which was draft-eastlake-card-map-08.txt ("ISO 7812/7816 Numbers and the Domain Name System (DNS)", issued February 2001, expired August 2001)—proposing the lookup of card issuers automatically based on the IIN using the domain name system. Although the domain name for doing this, reg.int, was registered by the Internet Assigned Numbers Authority (IANA) the proposal foundered due to the opposition of the ISO 7812 and ISO 7816 registration authorities, who were concerned that this proposal would make the ISO IIN registry publicly available.

The secrecy regarding the official ISO registry of IINs is probably motivated by concern for security through obscurity. However many people argue that this—and any attempt at security through obscurity—is pointless for a number of reasons. Knowing the contents of the IIN registry would be of limited help in carrying out fraud. The most common IINs (such as those for credit card companies VISA (credit card) and MasterCard) are already widely known, and someone seeking to reconstruct the ISO registry could find the most common entries just by asking a large number of people to tell them their card type and the first five digits of their card. Such publicly-contributed IIN database already exists.

Account Number The account number consists of digits seven to second last, a maximum of 12 digits.

Check digit The final digit is a check digit. This is calculated with the Luhn algorithm. ISO 7812, first published by the International Organization for Standardization (ISO) in 1989, is the international standard governing magnetic stripe identification cards, such as door entry cards, automated teller machine (ATM) cards, and credit cards. Credit card numbers are in fact ISO 7812 numbers. The maximum length of such a number is 19 numerical digits.

A ISO 7812 contains a single-digit major industry identifier (MII), a six-digit issuer identifier number (IIN), an account number, and a single digit checksum. The major industry identifier is considered to be part of the issuer identifier number.

Major industry identifier The major industry identifier (MII) is the first digit of the ISO 7812 number. It identifies the industry within which the card is to be used.

{| class="wikitable"|-----! MII Digit Value! Issuer Category|-----| 0 || ISO/TC 68 and other industry assignments|-----| 1 || Airlines|-----| 2 || Airlines and other industry assignments|-----| 3 || Travel and entertainment|-----| 4 || Banking and financial|-----| 5 || Banking and financial|-----| 6 || Merchandizing and banking|-----| 7 || Petroleum|-----| 8 || Telecommunications and other industry assignments|-----| 9 || National assignment|}

If the major industry identifier is 9 the next three digits are the numeric-3 country code from ISO 3166-1.

Issuer Identifier Number The first six digits, including the major industry identifier, compose the issuer identifier number (IIN). This identifies the issuing organisation. The American Bankers Association is the registration authority for IINs. The official ISO registry of IINs, the "ISO Register of Card Issuer Identification Numbers", is not available to the general public. It is only available to institutitions which hold IINs, issue plastic cards, or act as a financial network or processor. Institutions in the third category must sign a license agreement before they are given access to the registry. Several IINs are well known, especially those representing Credit_card_number#Credit_card_numbering.

Donald E. Eastlake wrote a series of Internet Drafts—the final of which was draft-eastlake-card-map-08.txt ("ISO 7812/7816 Numbers and the Domain Name System (DNS)", issued February 2001, expired August 2001)—proposing the lookup of card issuers automatically based on the IIN using the domain name system. Although the domain name for doing this, reg.int, was registered by the Internet Assigned Numbers Authority (IANA) the proposal foundered due to the opposition of the ISO 7812 and ISO 7816 registration authorities, who were concerned that this proposal would make the ISO IIN registry publicly available.

The secrecy regarding the official ISO registry of IINs is probably motivated by concern for security through obscurity. However many people argue that this—and any attempt at security through obscurity—is pointless for a number of reasons. Knowing the contents of the IIN registry would be of limited help in carrying out fraud. The most common IINs (such as those for credit card companies VISA (credit card) and MasterCard) are already widely known, and someone seeking to reconstruct the ISO registry could find the most common entries just by asking a large number of people to tell them their card type and the first five digits of their card. Such publicly-contributed IIN database already exists.

Account Number The account number consists of digits seven to second last, a maximum of 12 digits.

Check digit The final digit is a check digit. This is calculated with the Luhn algorithm.