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Before You ApplyEducational mortgage-readiness preparation

Applications · 8 min read

Issues that can affect a mortgage application

In short

There is no published list of things that 'fail' a mortgage application, and anyone presenting one is guessing. What can be said from the rules is narrower and more useful: a lender must assess affordability and must obtain evidence of the income it relies on, so anything that makes the picture unclear, unevidenced or inconsistent tends to create friction. Below are categories of issue worth preparing for. None of them is an automatic refusal, and none of them is a prediction about you.

Who this is for

  • People preparing an application who want to anticipate friction
  • Anyone who has heard alarming claims about what 'fails' an application
  • Applicants deciding what to organise or explain before speaking to an adviser

Key points

Unevidenced income is the clearest one

MCOB 11.6 requires the lender to obtain evidence of the income it takes into account. If income cannot be evidenced in a form the lender accepts, it is not that the income is disbelieved — it is that it cannot be relied on.

Inconsistency between what is stated and what is shown

Where a stated figure and a document disagree, someone has to resolve it. This is one of the few areas entirely within your control before you apply.

Committed expenditure that was not accounted for

The rules require expenditure to be taken into account. Commitments you had forgotten about do not disappear because they were omitted from a form.

Information recorded on your credit files that you have not read

The ICO explains lenders use credit reference data. The problem is rarely that the data exists; it is that people first see it during an application rather than months earlier when there was time to check it for errors.

A change of circumstances mid-process

MCOB 11.6 requires known likely future changes to income or expenditure to be taken into account. A change that arises after you apply is a change the lender will need to know about.

The property itself

A lender is also assessing the property as security. An issue can sit with the property rather than with the applicant, which is a distinction worth holding on to.

Timing and expiry

Documents go out of date and gathered evidence has a shelf life. Long gaps in a process can mean evidence has to be produced again.

Exceptions and things that vary

  • None of these is a rule. Lenders assess differently from one another, and one lender's difficulty is not necessarily another's.
  • No source consulted sets a threshold, a score, a waiting period or a number of adverse entries at which an application fails.
  • Some issues cannot be influenced at all. Separating those from the ones you can prepare for is more useful than treating everything as fixable.

How to work through it

  1. List what a careful reader would query

    Our suggestion: go through your own records as if you were a stranger reading them, and note every item you would want explained. That list is your preparation.

  2. Reconcile your stated figures to documents

    Our suggestion: for each element of income, find the document that evidences it and check the numbers agree before anyone else does.

  3. Write down commitments in full

    Our suggestion: list every regular commitment, including ones that feel too small to matter. Completeness costs nothing at this stage.

  4. Read your credit files early

    Our suggestion: obtain them from more than one agency, months ahead if you can, and raise anything factually wrong with the agency or the firm that reported it.

  5. Take the list to a qualified adviser

    Our suggestion: bring the written list rather than starting from memory. A suitably qualified FCA-authorised mortgage adviser can tell you what actually matters in your case; we cannot.

Illustrative example (not a real case)

Imagine someone who lists their income as a single figure, but whose payslips show basic pay plus a variable element. Nothing is wrong and nothing is hidden — but the two numbers do not obviously match, so somebody has to reconcile them. Listing each element separately from the start removes the friction. Illustrative only; it shows a preparation habit, not an outcome.

Illustrative only. Figures and situations in examples are made up to show a method. They are not typical, not a benchmark and not a prediction of any outcome.

What not to assume

  • Do not assume any item on this page would cause a refusal. None of them is described that way by any source we cite.
  • Do not assume there is a list of automatic fail conditions. We have not found one and we will not invent one.
  • Do not assume a difficulty with one lender says anything about another.
  • Do not assume something on a credit file is accurate simply because it is recorded.
  • Do not assume preparation changes a decision. It changes how clearly your situation can be understood.

Questions for a qualified adviser

We cannot answer these for you, and we do not introduce or recommend advisers. Take them to a suitably qualified FCA-authorised mortgage adviser of your own choosing.

  • Looking at my written summary, which of these points would you want more detail on?
  • What evidence would you need for the parts of my income that vary?
  • Is there anything here I should explain in writing before an application is made?
  • What would you suggest I do about the things I cannot change?

Check my readiness

Eight broad preparation questions. No figures, no personal details, no eligibility result.

Check my readiness

Related reading

A resource that may help you organise the next step

Optional educational preparation resources. Nothing here is mortgage advice, a lender or product recommendation, an eligibility assessment or a prediction of whether an application would be accepted.

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Sources

No statistic, regulator citation or third-party claim is published until its source is verified. Unverified entries are shown as placeholders.

Written by

Before You Apply editorial

Written by the publisher's editorial function, not by a named individual and not by a mortgage adviser. Before You Apply is not FCA authorised.

Reviewed by

Independent reviewer — to be appointed

No independent reviewer has been appointed yet. No review, qualification, FCA status or endorsement is claimed for this content.

  • Last fact-checked 2026-08-30
  • Not yet independently reviewed
  • Next review due 2027-02-28

Disclosure: this guide is educational. Before You Apply receives no payment for mentioning any lender, product or firm, and none are named.

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