Level 7 UK Diploma?

That's provided U. Portsmouth would admit Smartcard's uncle to advanced standing in the Master's with a PG diploma but no bachelor's of course. Way less of a problem in UK than here.

 

I found UK Universities to be very accommodating to adult learners who don't have a degree for admissions into graduate programs. Another example is Wrexham Glyndwr University. They offer a Masters in CS online conversion program and they don't need a prior bachelor's degree for entry - they would consider work experience. Maybe TS can check them out too. They have a range of Business programs too.

https://online.glyndwr.ac.uk/msc-computer-science/

 

One can get admitted into to top-up degree program but they also need to have the foundation knowledge to be able to graduate.
The universities that approve such progressions validate that previous learning from a provider is acceptable and having OfQual accreditation
also maintains a level of standard and quality to allow transition and be able to perform.
A colleague used such progression. When he transferred to the university he didn't expect the level of difficulty and academic challenges, it was extremely hard for him to graduate.
But it was worth the effort of earning a degree from a mainstream university.