A quick round of Google to said ISO gives a different view in my opinion (but im no expert in ISO..., so could be reading it wrong)
https://www.cdws.travel/downloads/rulesAndRegulations/78b25-18- ISO 24801-2 Autonomous.PDF
Says 20m and only after further training and/or with a guide/instructor to go deeper.
The ISO is a Standard not legislation, but in Egypt (for example) their laws use the ISO as guidance for their laws.
Each agency will have its own interpretation of what the ISO means. For BSAC our Ocean Diver qualification is EN 14153-2/ISO 24801-2 - 'Autonomous Diver' accredited. However, we include additional skills, like rescue of a buddy from 6m. Our Sports Diver qualification teaches many skills not associated with the ISO we use, ISO 11107 – ‘Nitrox diving’.
Our Ocean Divers are trained to a maximum of 20m, the actual certified depth - if less - is record in their training log. Sports Divers are initially qualified to 20m, then must undertake depth progression dives - with an instructor - to 25, 30, 35 and 40m to gain those depth limits (a requirement of the ISO Clause 4). Dive Leaders and above can do depth progression dives to 45 and 50m, but most diving at these depths is done on Trimix that we teach separately once someone qualifies as a Sports Diver and has its own depth qualifications [outside the scope of this discussion]. Remember the ISO does not set a maximum depth for recreational dives, as these vary around the world - for example in France its 60m.
Now the insurance companies may use the ISO Standards as the qualifying criteria for their policies. It’s got nothing to do with the diving agencies its commercial risk and payment limitation tactics. So read the insurance small print carefully, as misunderstanding one word can mean you’re not covered when you think you are.
I recently want on a diving trip and my dive insurance policy was clear I was covered to my certification level or 40m whichever was the shallower (I’m certified to 50m), the exception was if I was undertaking a rescue or assistance to another diver.