AIB (NI) A-Z Mortgage Guide


Want to know your EPC from your DIP? Our handy A-Z Mortgage Guide will help jargon bust the key words and phrases you are likely to come across during the purchase process so you can get back to planning your dream home!

Affordability calculator: An affordability calculator can help you find out potential costs for your future home. AIB’s calculator can help you estimate a monthly savings goal to reach your target.

Booking fee: Some lenders might charge a non-refundable fee to secure a particular fixed rate mortgage deal. AIB customers do not pay a booking fee.

Conveyancer: A Conveyancer is a specialist property solicitor.

Decision in Principle (DIP): A DIP, also referred to as an Agreement in Principle (AIP), is a letter that details how much a lender thinks you can comfortably borrow. This can be helpful when searching for a home and understanding your affordability.

EPC: EPC stands for an Energy Performance Certificate. An EPC gives a property an energy efficiency rating from A (most efficient) to G (least efficient) and is valid for 10 years.

Fixed rate: A fixed rate mortgage means that your rate and repayments will stay the same for a specific period of time, even when market rates change.

Green Mortgage:
AIB’s green mortgage rates are available to new customers buying their own home and existing customers who already have a mortgage loan with us (subject to eligibility criteria) which has an Energy Performance Certificate (EPC) rating in bands A or B.

Home insurance: You need to have home insurance (buildings cover) in place before you can draw down your mortgage. AIB recommends customers take out buildings and contents insurance for extra protection.

Interest: Interest is the fee charged on a loan used to purchase a piece of property. The amount of interest owed is calculated as a percentage of the total amount of the mortgage issued by the lender. Mortgage interest compounds and may be either fixed or variable.

Joint mortgage:
A joint mortgage is when you apply to borrow money to buy a home with someone else, like your partner, a friend or a relative. They'll be jointly liable for the mortgage payments.

Key Facts Illustration (KFI):
Also known as ‘ESIS’, this is a document that helps you compare the costs and features of several mortgages.

Loan to Value: Loan to Value (LTV) ratio is a measure comparing the amount of your mortgage with the appraised value of the property.

Mortgage: A mortgage is a type of loan from a bank or building society that helps you buy a property.  To find out more about AIB’s mortgage products, visit our website here.

Net income refers to your take home income every week or month after deductions for tax, pension, student loan etc.

Offer: This is a formal offer from the bank and means that your mortgage has been fully approved, subject to any terms and conditions.

Proof of income: To show sustainable income, you will be required to share proof of salary or income to your bank such as payslips and financial accounts. These documents will vary based on if you are employed or self-employed.

Quantity surveyor: A person who calculates the amount of materials needed for building work, and how much they will cost.

Rates: A mortgage rate is the interest rate charged for a home loan. Mortgage rates can either be fixed at a specific interest rate, or variable, fluctuating with a benchmark interest rate.

Stamp duty: This is a tax you pay when you buy a property. In Northern Ireland, no stamp duty is due on the first £250,000 of a residential property (provided it's your main residence and isn't a second home / additional property) – though that threshold is £425,000 if you're a first-time buyer.

Turnkey: A turnkey property is a fully renovated home or apartment building that is ready to be moved into. 

Underwriting: The underwriting process is where your application and its supporting information are fully assessed to ensure that the mortgage is affordable and meets the bank’s lending policies.

Valuation report: A standard valuation report makes sure that the property is of sufficient value and quality. AIB offers free standard valuations across many of our mortgage products.

Welcome: AIB’s expert team of mortgage advisers will always make you feel welcome! To schedule a call with one of our mortgage team members, call 0345 600 5925 or visit

X (Sign here): You may come across an ‘x’ in various documents. This indicates a place for a signature.

Year-end statement: A mortgage year-end statement will provide a summary of transactions made on that account for a 12-month period. It will include details of interest that has been charged.

Zen: Trust AIB with your mortgage, so you can relax and enjoy the tranquillity of your new home. Visit to get started. 

Whatever your mortgage question, you can bank on us.
Whether you are buying your first home, moving home or just have a mortgage question, our expert team of mortgage advisers are here to help. Schedule a call with one of our mortgage team call 0345 600 5925 or visit our dedicated mortgage homepage.