You may have it. But do you know it?

Ireland will, at long last, introduce postal codes in early 2015. It begs a question for ecommerce practitioners everywhere – at what point is it wise to assume that all inhabitants of Ireland know their codes so that you can demand their postal code (as a required field) rather than just enquiring after it?

In many countries with postal code systems it’s hard to imagine not knowing your postal code. Or, indeed, finding somebody who does not know there is a code. But this is not an unusual situation in many countries. Indeed, I remember from my own childhood how hard it proved to be to persuade my own older relatives to use their postcodes, and Royal Mail had to exhort the “USE THE POSTCODE” cancellation stamp on letters for many years before its use became universal.

There are still many countries and territories about the world (about 76) without postal codes, and in many of those, little progress is being made to introduce one. Yet there are countries which have systems which are not used, for a variety of reasons.

There is a clear difference between having a system and using it. The Universal Postal Union (UPU) pressures its members to introduce structured address systems, including postal codes, and some countries oblige by having systems that they choose not to use. Bahrain is a good example, where the code isn’t used ostensibly because sorting is not yet automated. Vietnam changed from a 5-digit to a 6-digit postal code system back in 2004, yet recent discussions on the various forums welcomed the 5-digit code as a new postal code, though it is almost a decade old, because most Vietnamese didn’t know about it – or indeed that a code had also existed before 2004.

I have had people living in countries, such as Honduras, swear blind to me that there is no postal code system in their land, even after I point them to the official site describing the system. In some countries, plans for new or altered systems are pulled for a number of reasons (e.g. Jamaica, Serbia and Mauritius) leaving people in limbo as to whether to use codes and, if so, which ones.

Clearly, you can have a postal code, but is it used? And does anybody know about it?

This has obvious implications for companies collecting international address data for ecommerce. In one way it is fortunate that many companies are behind in their understanding of address systems as they may not demand a postal code in a country which has one but where nobody knows their code or they are not used, by dint of they themselves not having heard about it. But where systems are known about, making postal code fields required when not every person is aware of their codes is inviting trouble. Customer will either have to make up data to make their purchase, filling the company’s database with polluted data, or those customers will go elsewhere to make their purchase. It’s a tricky balancing act, and one that online address validation systems can help overcome.

For more information on international addressing, download our whitepaper on understanding international data.