Open Banking and your mortgage, and what read-only really means

If you have ever been asked to connect your bank account to a financial service and felt a flicker of hesitation, that is a healthy instinct. You should know exactly what you are agreeing to before you do it.

This piece explains what Open Banking is, what read-only access actually means in practice, and why it can make the mortgage process considerably less painful.

Open Banking is a regulatory framework, not a fintech gimmick

Open Banking was introduced in the UK in 2018 following a mandate from the Competition and Markets Authority. It is not something a startup invented. It is a standardised, regulated way for banks to share your financial data with third-party services, but only with your explicit permission, and only through FCA-authorised providers.

When a service offers Open Banking connectivity, it is working within that regulated framework. The providers facilitating the connection are authorised by the FCA. That is the baseline.

Read-only means exactly that

The phrase "read-only access" gets used a lot. It is worth being precise about what it means.

When you connect an account through Open Banking for information purposes, the service can see your transactions and balance history. That is it. It cannot initiate a payment. It cannot move money. It cannot set up a direct debit. It cannot change your account details. It cannot do anything that modifies your account in any way.

Think of it like giving someone a printed copy of your bank statement to look at. They can read the numbers. They cannot reach into your account.

This is enforced at the infrastructure level, not just by a promise in a privacy policy. Account information access and payment initiation are separate, distinct permissions under the Open Banking rules. A service that only requests account information access is technically incapable of moving your money.

You log in with your bank, not with us

Here is the part that surprises many people: when you connect your account, you authenticate directly with your own bank.

The connecting service never sees your banking password, your PIN, or your one-time passcode. You are redirected to your bank's own login screen, the same one you use when you log in normally, and your bank handles the authentication entirely. Once your bank confirms your identity, it issues a secure token that allows the connecting service to read your data. Your credentials stay between you and your bank.

This is a deliberate design of the Open Banking standard. The connecting service is never in the middle of your login.

You are in control

Before any data is shared, you choose which accounts to include. You might connect a current account and leave a savings account out. That choice is yours.

You can withdraw consent at any time. If you decide you no longer want a service to have access to your data, you can revoke that through your bank's app or through the service itself. Once you do, access stops.

No one holds your data hostage. The control sits with you throughout.

Why this matters for a mortgage

The traditional mortgage application involves a lot of paper. Payslips, three to six months of bank statements, sometimes printed, sometimes scanned and emailed, occasionally lost and re-requested. A broker or lender then manually reviews these documents to build a picture of your income and spending.

That picture is also always slightly out of date. A bank statement you printed last week reflects last week. The lender still has to ask whether anything has changed.

Open Banking offers a different approach. Instead of documents, a lender or a tool can read a real, current view of your transactions directly from your accounts. Income patterns become visible without you having to chase payslips. Regular commitments show up clearly. The data is more complete and more current than a stack of PDFs.

For self-employed applicants, this matters even more. Demonstrating income through bank data alongside Government-sourced income records (HMRC) can give a much fuller picture than a handful of statements.

This does not remove the complexity of a mortgage application. But it reduces the paperwork burden and gives everyone, you included, a clearer starting point.

What we are building at Moxim

At Moxim, we believe you should be able to see where you stand on a mortgage clearly, honestly, and from your own data. We are building an Open Banking-powered mortgage-readiness layer: an illustrative read of your affordability, and a portable credential you own and can take to any broker.

We showed our work at the FCA Mortgages TechSprint 2025, and the work is ongoing. When you connect your accounts with Moxim, which opens with early access, read-only means read-only: we see your transactions so we can show you an illustrative picture. We never see your password. We never touch your money. And to be clear about roles: the Open Banking connection itself runs through FCA-authorised providers Moxim works with; Moxim is not yet FCA-regulated itself.

Everything Moxim shows today is illustrative and educational, never a quote, an offer, or a lending decision. Moxim is not yet PRA-authorised or FCA-regulated. If you would like to see where you stand, see the experience.