Inside the Nudge Unit

in one series of letters from our tax department, the HMRC, taxpayers were given a web address where they could find the online tax forms to complete. If the recipient typed in the address, it took them to the HMRC’s webpage with the tax form clearly on it. All the person had to do then was click on the form and, of course, fill it in. It turned out that just under one in five people who received these letters did indeed go on to fill in the form and pay their tax as a result. We ran a trial testing a tiny change. The trial compared the effect of the original letter to one almost identical except that the web-link took people directly to the form, instead of to the page with the form on it. In other words, it saved people a single click, albeit at the cost of a couple of extra characters of text. The result? A 22 per cent increase in the proportion of people completing their tax forms in response to the letter.