Many people spent the end of 1999 counting down the clock, but not for the reasons you might expect on New Year’s Eve. Instead of celebrating bringing in the New Year, there was widespread concern that when the clock struck midnight, the world would grind to a halt.

The Y2K bug, also known as the millennium bug, refers to the potential computer errors that were predicted to wreak havoc when the year changed from 1999 to 2000. The anticipated issues stemmed from many computer programmes only using two digits to represent the year, and thus making the 2000s indistinguishable from the 1900s, meaning, for example, the year 2000 or 00 would be read as 1900. The vulnerabilities of this cutting corner exercise were revealed in later years but did not prompt programmers to recognise this as an imminent threat until the mid-90s. 

Ominous news reports warned the public of apocalyptic repercussions, including power plant malfunctions, empty bank accounts, dams flooding, and unintended missile launches. This caused panic across the globe and prompted people to stock up on survival supplies and prepare for the worst. Although many believe that the Y2K bug was a hoax or exaggerated by the media and conspiracy theorists, others are adamant that without the efforts made by computer experts and programmers, catastrophic implications would have happened. In fact, the UN international Y2K Coordination Centre estimated that the Y2K bug required thousands of person-years of effort and cost between $300bn to $600bn to prevent.

Today, financial firms face a similar issue - albeit on a smaller scale - where Firm Reference Numbers (FRNs) will reach the six-digit limit (999999) in 2023. Currently, six-digit FRNs are used to identify financial service firms uniquely. However, because of the volume of applications and notifications the Financial Conduct Authority (FCA) receives, this will change to seven-digits for newly registered firms. Organisations will have to implement system updates for the longer numbers to ensure day-to-day operations are not impacted. Any organisation using FRNs will risk being affected by the increase in digits if they do not process these correctly. For example, if financial services’ systems can’t process seven-digit FRNs, they will either fail to process transactions or potentially – just as seriously – use incorrect, truncated FRNs. Lessons should be learnt from the Y2K bug in that organisations should not underestimate the impact of a minor change, and the potential consequences of our reliance on technology.

Although the FCA has not confirmed a date for when the changes will come into play, firms must be forward-thinking and prepare as soon as possible to avoid any system failures. Criterion has been working through the more than 20 affected Standards to support our customers make these essential changes. So far, we have made the necessary changes to the following:


Keep an eye on our website and social media channels for further Standard FRN updates.