Insight shows that one in 10 people in the UK operate in the hidden economy, a term for economic activities hidden from HM Revenue and Customs (HMRC). Notably, 65 percent of these individuals are most likely operating side hustles and are largely unaware that they should be registered for tax.
This is exactly why HMRC partnered with Audiomob and harnessed our Standard and new Moments Audio Ads for its Help for Hustles campaign. The campaign supports young adults aged 18 to 34 earning income through side hustles to understand their tax obligations. It aims to help those with a side hustle get their tax right and avoid unexpected tax bills by providing clear, straightforward guidance on when to tell HMRC about additional income.
Audiomob helped to educate people about the £1,000 tax-free threshold, inside mobile games using our non-intrusive audio formats. Players continued their gameplay while still receiving the full message, and the response was extremely positive.
Below is a breakdown of the key findings:
An Audience That Keeps Listening
Mobile gaming offers one of the most powerful touch points for young people.
Audiomob delivered HMRC messages across millions of gameplay moments. The campaign achieved a 95.2 percent listen-through rate. This means almost every player who heard the message listened from start to finish without stopping their game.
High reach matters, but high attention matters even more.
Awareness That Cuts Through
The campaign generated strong message recall across the full audience and even more so among people who earn additional income through side hustles:
27 percent recall across the entire group
33 percent recall among confirmed side hustlers
These results are a positive sign: when players receive information in a respectful, non-disruptive audio format, the message is likely to be remembered.
Driving Real Action
One of the most encouraging results came from behavioural responses.
Nine in ten respondents said they had taken action or intended to take action after hearing the ad.
For HMRC, this means that nearly all players who heard the campaign messages have either taken steps or intend to take steps to understand their tax obligations and check whether they need to report additional income.
It also reinforces the power of audio as a tool for driving behaviour change.
A Format Designed for Impact
Mobile gaming provided a relevant environment to reach people aged 18 to 34. Audiomob’s patented non-intrusive technology allowed HMRC to communicate in a way that respects user attention and maintains the experience players expect.
This campaign delivered:
3.45 million impressions
19.9 thousand clicks
0.59 percent click-through rate
strong uplift across all brand lift metrics
The combination of accessibility, timing and seamless delivery enabled the campaign to reach players at moments when they were most open to receiving the message.
A Successful Pilot for Moments Audio Ads
We are proud to support HMRC in piloting our Moments Audio Ads and helping people earning additional income through side hustles to understand tax obligations.
As digital behaviour evolves, in-app audio is becoming one of the most effective ways to communicate with mobile-first audiences.
This campaign demonstrates that when information meets in-app audio, it not only reaches the right people but also drives them to act.
