Lenders need to look at lots of factors before deciding whether to offer a mortgage - and your credit file is just one.
Income assessments are used to calculate the maximum the lender can offer. For self-employed applicants or contractors, you will usually need three years of trading accounts. However, lenders are all different, and so a broker can recommend the lender whose policies align with your income structure and trading history.
Outgoings are also reviewed, with debt repayments deducted from your income to calculate whether you would be able to afford the mortgage costs comfortably.
Your age is a factor for some lenders, who place age caps on the maximum age you can be at the point of application or the end of the mortgage term.
The property is analyses to check that it offers suitable security against the size of the mortgage loan you are applying for. Non-standard properties or unusual homes are less saleable in a repossession scenario, and therefore a specialist lender may be required.
Loan to Value refers to the mortgage application amount against the value of the property. The higher the LTV, the riskier the loan - so, for example, if you want to buy a property worth £200,000 and need a £100,000 mortgage, the LTV is only 50% and is easier to achieve competitive interest rates against.
Deposit source matters since lenders have rules about where they can accept a deposit. Savings and gifts from immediate family members are the most commonly accepted sources.
Credit history is always assessed for any mortgage application. Most high street banks will automatically reject any applicant with any bad credit. In contrast, others will be far more pragmatic and may ask to clarify the circumstances that led to the issues.