I checked this with Monzo, and this is what they replied:
“When you open an account we run a soft credit check. This leaves a “soft footprint” on your credit report, meaning that it’s not something lenders are allowed to take into account when making lending decisions. You can read more about this on our blog.
We currently report to At the moment we only report to TransUnion (previously known as CallCredit). We chose TransUnion after carrying out a due diligence process with all the major credit reference agencies and deciding they were the best fit for us.
In the long run we aim to report to multiple credit reference agencies so we give our customers the best chances of being able to borrow but we’re not quite there yet.
Until we do, Monzo will only show up on your TransUnion credit report which you can view by logging into your Credit Karma account.
So you know, each agency has their own scorecards on how they estimate a customer’s credit score and certain factors on a credit file might weigh more favourably/negatively in one credit agency’s scorecards over another’s.
If you’d like to learn more about credit scores you can check out this blog post here. And this blog post here will tell you how to build your credit score. Let me know if you have any questions about this — I’d be happy to explain.”
So I guess the answer is technically yes. If you’re trying to get a mortgage or loan, and the lender doesn’t use the same credit agency that Monzo use, then you may be unable to borrow from that lender. So dependent on your immediate circumstances, it might be better to stick to your current traditional bank until Monzo increases, at the very least, to Experian.