Self-certification mortgages are for people whose income is difficult to assess using the standard methods adopted by most conventional mortgage lenders. They allow you to 'self declare' your earnings. Bonuses, commission and seasonal work can cause income to vary over time or be difficult to guarantee and this may not be considered acceptable in order to get a mainstream loan.

Many customers who go on to be excellent mortgage customers with specialist lenders routinely fail credit scoring processes with mainstream lenders. While most self-certification mortgages are also available to the self-employed, they are not exclusive to them and some of the following groups also opt for this type of product:

• Unsalaried company directors
• Contract workers (increasingly common in technology-based industries)
• Commission-based workers (often in sales, recruitment etc)
• People with seasonal earnings
• Those with more than one income
• City workers or others who receive a high annual bonus
• Employees from other sectors such as the airline industry, who have complicated systems of bonuses and allowances that make conventional documented proof of income problematic.
• Borrowers on a low wage who have an inheritance fund or other family income
• Freelance workers Self-certification is the process by which the amount that a customer borrows is based on what they claim is their income as stated in a signed declaration in the application form, but where they don't have to prove it on the basis of their accounts.