Belron’s online customer experience manager Craig Sullivan gave a great presentation at last week’s Online Marketing Masterclasses event, and one of the many nuggets contained within was that strict postcode validation was causing 2.5% of customers to abandon.

The problem that Craig discovered was that customers were entering the letter ‘O’ when a zero was required, triggering an error message. Since they may have been unaware of their mistake, this frustration was causing customers to abandon.

To get around this, the forms now anticipate these errors so that users would continue through the form, not even knowing they had made a mistake, an elegant solution to the problem.

It really should be something that every online retailer should do in its registration or checkout process, so I’ve been checking some of the better known UK etailers to see how they handle this error.

Retailers that fail the postcode test are:





The retailer does at least attempt to instruct customers to enter the postcode in the correct format, but doesn’t anticipate this particular input error:

I could show you more screenshots, but suffice to say, eight of the ten e-commerce websites I tried this on produced an error when I entered the letter ‘O’ when a zero was called for. The others were Comet, John Lewis, M&S, and ASOS.

Those that passed the postcode test were HMV and, both of which simply ignore the error and allow users to continue, thus removing a potential source of friction.

There are other issues with form entry on e-commerce sites where strict validation can cause errors for customers, and the key is to test for the common errors that are causing abandonment and make forms flexible enough to deal with these issues.

Currys, John Lewis and the other sites which produce errors when customers enter postcodes like this should look at their analytics to see if this issue is affecting them. If so, this one change to postcode entry could an easy, quick way to reduce abandonment rates.