What Is the Best Way to Get a Mortgage Agreement in Principle (AIP)?

Are you trying to get a Mortgage Agreement in Principle (AIP) before you start seriously searching for the ideal property? It is often one of the first steps that most buyers take and can help you narrow your focus on exactly what you can realistically afford and not just what you hope your budget might be.

An AIP is often what helps kick-start the buying process and is often the point when the buying journey starts to feel real. It provides you with an estimate of what you’re likely to be able to borrow and has a variety of benefits that can help shape the search for your dream home.

But how easy is it to get a mortgage in principle, and what information do you need to have ready?

In this article, we walk you through exactly what a mortgage Agreement in Principle really is, how you can get one, and what information you will need to share with your chosen lenders. Let’s jump in.

What Is a Mortgage Agreement in Principle (AIP)?

A mortgage Agreement in Principle (AIP) is a lender’s early indication of how much they may be willing to lend you. This is an estimation based only on an overview of your current financial position, and is usually the first step in a buyer’s journey where real figures start to take shape to give you a clearer idea of what you could afford.

For many buyers – especially those who are applying for a mortgage for the first time – it can be easy to get lost in all the jargon that is used in the world of mortgages. Alongside an Agreement in Principle, you may also come across terms like a “Mortgage in Principle”, or a “Decision in Principle”. In reality, each of these terms all refer to the same idea, and they are often used interchangeably – so don’t worry if you suddenly hear a few different terms along the way.

However, a key distinction that needs to be made – that all the terms listed above share – is that an AIP is not a formal mortgage offer and does not guarantee the approval of your mortgage application. Additionally, an AIP is usually only valid for 3 months, depending on your chosen lender. After this time, you would need to reapply for a new AIP.

Instead, an AIP acts as a guide, providing you with an early indication of what you could borrow, and can be used as documentation to demonstrate to sellers and estate agents that you’re a serious buyer.

In comparison, a full mortgage offer would only be offered once a lender has completed a full and detailed assessment of your application. This would typically include a full credit check, income verification, and a review of your financial situation through bank statements and paychecks.

In short: Getting a mortgage agreement in principle is the first step in outlining a realistic budget, helping you focus your search on properties that are realistically within your price range.

What Are the Fastest Ways to Get an AIP?

When looking to get an agreement in principle quickly, the actual turnaround time will not just depend on the route you take, but also how prepared you are. In many cases, an AIP can be arranged within the same day, but this will often rely on how quickly you can provide all the necessary information.

With that said, with everything in place, a trusted mortgage broker will usually be able to submit and receive an AIP very quickly. For example, at Boon Brokers, once you have completed our easy fact find and provided your documents, an AIP can often be arranged within the same working day or shortly after.

Outside of this framework, and in complex income cases, timelines can vary. This will typically be the case if a lender needs to carry out any additional checks, such as credit scoring issues, or confirming your average income.

It’s important to note that in practice, the fastest route will not always be about sending your application for an AIP the quickest. Rather, it’s about completing the application correctly, avoiding any follow up delays or need for further clarification.

Those with typical income patterns, straightforward financial circumstances, and a chosen lender already in mind, may benefit from a streamlined process. However, for anyone with a more complex income pattern or concerns about missing documentation or their credit score, taking a more considered approach by working with a trusted mortgage broker can help you avoid delays or the need to reapply later on.

In simple terms, the fastest route will usually depend on:

• If you have already chosen your lender and have all the information required ready at hand, then applying directly with that lender can be a quick way to get an AIP secured.
• If you’re unsure what information you need to provide, want help finding the right lender and mortgage, or would rather keep the process from AIP through to a full mortgage offer as simple as possible, working with a trusted mortgage broker could be the right option for you.

At Boon Brokers, our dedicated mortgage experts can help you get an AIP in place by finding a mortgage that suits your circumstances and applying directly to the right lender. To get an AIP in place, all we need from you is a completed fact-find form, which can be filled in online through our portal, and documents to verify the information.

What Information Do Lenders Need Before Issuing an AIP?

Before issuing an AIP, lenders will require an overview of your financial situation. This will include key details about your income, spending, and credit history, all of which will help them estimate how much you may be able to borrow.

At this stage, lenders will usually rely on the information you provide, rather than asking for full documentation or evidence straight away. It can be a bit like submitting details for a rough quote – the information you provide should be enough for a lender to estimate, but with nothing confirmed until all the details have been checked in more detail further down the line.

This is exactly why accuracy matters. It’s important to always be honest and upfront with the information you provide. Should something not quite add up later in your mortgage application, then the estimate in your AIP could change – sometimes significantly – which can slow things down or affect the outcome of your application.

Think of it like this, in an AIP lenders are trying to answer one question: how much can you realistically afford to borrow? The information you provide will help them build that picture.

To help you prepare, we’ve created a simple checklist below of all the key information that lenders will typically ask for when assessing your AIP:

While the table above provides you with a helpful overview, if you’re unsure on your next steps, this is where working with a trusted mortgage broker can help simplify things. At Boon Brokers, we take the time to understand your needs and will guide you through a simple fact-find form that can be completed online. Our aim is to make your mortgage journey as simple as possible, providing you with all the information you need so that your AIP can be arranged without stress.

Can You Get a Mortgage Agreement in Principle Instantly Online?

Yes, it is possible to apply for an agreement in principle online and receive a decision within minutes. This is because most lenders today will use automated systems that can process applications quickly, and as an AIP is based on an initial overview, this process can be completed in a matter of minutes.

With that said, while you may be able to get an instant result online, that doesn’t always mean that it will be the most accurate or suitable. As we touched on earlier, the quickest route is not always the best route, what’s most important is that you receive the right results.

If your financial circumstances are more complex – for example, if you’re self-employed, have multiple income streams, or a more detailed credit history – then lenders may need to carry out additional checks behind the scenes. In these cases, decisions may take longer, or the initial result may not accurately reflect your full options when it comes to a more detailed review of your full mortgage application.

If you’re unsure whether or not you’re on the right path to securing an AIP that will help you, working with a trusted mortgage broker can help shape your mortgage plans. At Boon Brokers, we don’t rely on a quick, one-size-fits-all result. We take the time to understand your circumstances, ensuring that we find the mortgage that is right for you.

Do You Need a Mortgage Broker to Help You?

While you do not need a mortgage broker to get a mortgage AIP, having the right support in place can make the entire mortgage process far more straightforward, from start to finish.

As we’ve explored throughout this article, getting an AIP isn’t just about speed, it’s about getting an accurate view of what you can borrow, avoiding delays, and making sure your borrowing estimates reflect your circumstances properly. Small details, inconsistencies, or applying in the wrong place can all slow things down or lead to an outcome that doesn’t quite match your expectations.

At Boon Brokers, our dedicated mortgage experts bring that clarity from the start. Rather than relying on a single lender’s assessment, we take the time to review your case in full, find the mortgage that best matches your needs, and make sure your AIP is arranged with your chosen lender as soon as possible.

As a fee-free, whole-of-market broker, we have access to the wider mortgage market and will compare a wide range of lenders to find a mortgage that fits your circumstances, before arranging your AIP and guiding you through the next steps. With our quick and simple online fact-find, you can get started in minutes, knowing your application is being handled with care by professionals.

If you’re ready to get your AIP in place or want to explore your mortgage options in more detail, contact Boon Brokers today and take the next step in your mortgage journey.

For a full breakdown of the mortgage timeline, read our guide: The 2026 Timeline to Buying a House in the UK, which covers each stage from offer through to completion.