Don’t Let Postcode Entry Problems Spoil Your Checkout Process

Even if a customer has had a good experience on your site, found the right product at the right price, the checkout process still represents a hurdle to be overcome.

One common issue with online checkouts, and one which should be easy to solve, is postcode entry.

In this article, I’ll identify some of the most common issues, look at where some major ecommerce sites may be losing sales, and how to solve these problems.

Problem 1: Postcodes with or without spaces

Some customers will enter postcodes with a space in the middle, and some won’t. Likewise, some sites want the space, and some don’t.

For example, won’t accept postcodes without the spacing:

This produces an error message, which does at least tell me it needs a space, and capital letters.

A better approach would have been to make this clear next to the form field. This would save customers the extra effort and frustration of having to re-enter the postcode.

Also, why be so strict about spacing and capitals? I’d advise Tesco to take a look at its site data and see how many customers are being tripped up at this stage.

Websites should accept postcodes with or without a space, and whether they are in capitals or lower case.

It’s an easy mistake to fix, and one which, especially for a company of Tesco’s size, could make a difference to its conversion rates.

Problem 2: not using postcode lookup tools

Adding postcode lookup is a very useful shortcut for customers. It avoids the need for them to enter full address details and therefore makes checkout forms a little less painful.

It also has the advantage of eliminating potential errors and typos which may lead to problems with delivery.

For example, adds a simple lookup tool and then displays a list of addresses for that postcode. It also accepts postcodes in lower case and with or without a space:

It’s also a must on mobile commerce sites. With form filling already a frustrating process on a smaller screen, postcode lookup is a vital shortcut, and one which will maximise conversions.

Problem 3: ‘O’ instead of zero, ‘I’ instead of 1 etc…

This is a common issue, and one which many e-commerce sites fall foul of.  Customers can easily enter the letter ‘O’ when a zero is required, or an ‘i’ instead of the number one, often triggering an error message.

Since they will often be unaware of their mistake, customers are likely to repeat it, becoming more frustrated with each error message. The likely result, unless they realise their mistake, is that they will abandon the purchase.

Many retailers will show an error message in this case, including Amazon, Tesco and, in this example, Argos:

Since the sites aren’t detecting this potential issue, the error messaging is completely inadequate, which just compounds the problem.

That’s three of the biggest online retailers in the UK. How many potential sales are they losing thanks to this issue?

This is something which was pointed out by Belron’s Craig Sullivan at an Econsultancy event a few years ago.

He found that this was happening on Autoglass and other Belron sites, and the forms now anticipate these errors so that users would continue through the form, not even knowing they had made a mistake.

This was causing 2.5% of customers to abandon the quote process

This was an excellent solution to the problem which avoids shifting blame onto the customer and allows them to continue through the checkout.


  • There are other potential issues, such as shifted characters  (i.e. £ instead of 3, $ rather than 4) but the answer is generally the same – find out what the common issues on your site are and correct them.
  • Another important improvement is to make it clear what format you are expecting customers to use when entering postcodes. If you want the postcode in capitals with a space in the middle, say so.
  • After all, the fewer error messages customers encounter during checkout, the more likely they are to complete the purchase.