Put a landline number not a mobile on applications.
Number that appears as landline is approximately £50 per year:
The question is - will such a virtual landline work? Do the credit rating agencies have ways of knowing that it's just a gimmick?
EDIT / UDPATE 2: https://forums.moneysavingexpert.com/showthread.php?t=5561716#19
The stability aspect doesn't come from a landline number as such but comes from a telephone directory entry which can be tracked back to you and your address. It's actually a form of address verification almost equivalent to the electoral roll.
I find it fascinating that in 2019 era of surveillance, privacy awareness, GDPR, we ask you for a cookie, cannot visit a website because you are in the EU, people are freely giving away their home addresses: https://www.thephonebook.bt.com/person/
On a personal note, I see gross deficiencies in the current credit score system and I'm planning to establish a new, transparent, open-source standard. Me being a 100 baseline, obviously.
EDIT / UPDATE: Since I was downvoted, checked what questions are on-topic here: https://money.stackexchange.com/help/on-topic
Best practices for saving for retirement, education, and other goals
It is related to saving - not spending money for a gimmick, to a goal such as mortgage.