REV Freelance is a useful little side hustle for anyone that can type at a reasonable speed!
The idea is that you work as a freelancer and transcribe audio files, into words, and get paid for your time. It's an American company, and they pay in USD $ via PayPal, weekly, for the work you have done for them. The normal rates are between $0.30 - $1.10 per audio/video minute, and they generally have hundreds of jobs on the go, at any given time, and you can choose which job you would like to complete.
There are no minimum or maximum number of jobs you need to complete, it's totally adhoc, you just work as and when you choose, which is super useful for anyone looking for occasional work, or if you are looking for an additional, and regular, revenue source, you can work on more projects, with many people actually performing the tasks as a full time job.
You can also work as a captioner for video work, and if you have a 2nd language, could earn even more by transcribing from English into another language, with the rates going from $1.50 - $3.00 per audio minute.
In order to be considered as a transcriber, you need to perform a few online tests, to make sure you are of a high enough standard to be able to do the job, and once passed, you can normally get started within a couple of days.
You will be a self employed contractor, and need to account for your revenue yourselves, to HMRC, as you will not taxed.