What is a mortgage in principle & how long does it last?

Buying a house might be one of the items on most adulting to-do lists. This milestone is going to require a lot of effort, especially in terms of financial power. 

Are you currently looking to buy your first house? Or maybe you’re planning to move to a bigger house in preparation to welcome a new life into your family? Have you been saving for a mortgage to purchase your dream house? Let’s go over the initial document you will need to gauge your qualifications to borrow funds: the mortgage principle.

You may also be familiar with other terminologies for a mortgage principle, such as an agreement in principle, a decision in principle, an approval in principle, or a mortgage promise. 

In this post, we’re going to share all about the mortgage in principle: what it is and how long a mortgage can last when you want to purchase your first house?

What is a Mortgage in Principle?

When you’re a first-time home buyer, you can take advantage of the mortgage in principle to find the estimated amount of money the bank can loan you on a mortgage. Even if you need to remortgage your home, an Agreement in Principle (AIP) can help you and your real estate agent to find a house that you can afford to purchase with a mortgage. 

Having your mortgage in principle accepted does not guarantee an automatic approval for your full mortgage application. Nevertheless, applying for a mortgage in principle will be a good opportunity for you to avoid any potential problems for the real deal.

What do you need to apply for a Mortgage in Principle?

Before applying for a mortgage in principle, make sure that you’ve prepared the following information:

  • Income (including salary, bonuses, benefits, pensions, investments, etc.)
  • Outgoing (including childcare, school fees, travel costs, etc.)
  • Any existing credit agreements
  • Address history in the UK for the last three years


Depending on your situation, your application for your mortgage in principle may be rejected. This will be the case if you’ve shown poor performance on the information above or failed to provide reliable proof for your statement. 

Is it mandatory to have a Mortgage in Principle?

Applying for a Mortgage in Principle is not compulsory, but it tremendously helps as a first-time home buyer. Not only will it give you a clear idea about how much you can afford, it can also help you find a suitable house with the right budget to get your mortgage approved. 

Getting a mortgage in principle is fast and simple. In most cases, your application will be free of charge. Just like the saying “better to be safe than sorry”, it is better to be prepared with a mortgage in principle than to jump headfirst into a mortgage application. 

Why do you need a Mortgage in Principle?

A mortgage in principle will let you know how much you can realistically borrow. This keeps you from applying for a mortgage that is too big for you and getting turned down. It is worth noting that a mortgage rejection will be recorded on your credit report, which will impact your credit score and can hurt your next mortgage application. 

If you happen to receive a mortgage in principle that is lower than your expectations, you have the freedom to seek out other lenders and try to get an improved offer. However, you should be aware of whether the lender will conduct a soft check or a hard check on your credit score. Multiple hard credit checks can damage your score since it will make you appear as if you’ve been rejected for credit several times.

When can you apply for a Mortgage in Principle?

There are no definitive signs as to when you should start applying for a mortgage in principle. Whenever you’ve felt ready to commit and start seriously seeking your dream house, you should start submitting your application. 

Aside from the clear practical benefits, this will help you focus and serve as a reminder of your goal: the dream house that you can actually afford. 

How long does a Mortgage in Principle last?

You can apply for a Mortgage in Principle through either a bank as your potential lender or a mortgage broker. The latter is probably the easiest, since they will have access to a greater range of mortgages and can provide you with mortgage options that are more suitable for you. Keep in mind that a mortgage broker can also help shorten your overall mortgage application process.

Applying and sorting for one should take an hour at most, if everything runs smoothly. You can get the result of your Mortgage in Principle application instantly, with some banks can proceed with it for only around 15 minutes. It lasts for around 60 to 90 days, depending on the lender. With a mortgage in principle at hand, you can go through your house-hunting journey with a stronger backing to your offer.


In essence, a Mortgage in Principle will give you an idea of how much the bank as a lender can loan the money to you, which is especially important if you’re a first-time homebuyer. Showing this document to estate agents and vendors can prove that you’re a serious buyer and that your offer is realistic. 

Depending on your potential lender, the Mortgage in Principle will be valid for around 2-3 months, giving you a chance to start your house-hunting process. If you’re lucky, you’ll probably get to move to your new house within this period. If not, you may need to renew your Mortgage in Principle if you haven’t found your dream house within the time period. There shouldn’t be any complications, especially if your economic and financial situations haven’t changed significantly. 

Essentially, applying for a Mortgage in Principle is a straightforward process. However, there is still a possibility to get it rejected, which can also hurt your credit score. Once you’re serious about purchasing a house, the most important thing is to fix your finances first so you can get ahead to apply for a Mortgage in Principle, which will increase your chance to get your mortgage application approved.