Skip to content
Buyer AgencyFinancial adviceHousing adviceLegal advice
Home DreamsMeet the teamPricesHome buying guidesSearch homes
Log in 72 600 400 Dansk
Home / Home buying guides / F1, F3, and F5 loans: Which loan should you choose?

F1, F3, and F5 loans: Which loan should you choose?

4 min read · Jovica Stanković · 6 October 2025

F1, F3, and F5 loans: Which loan should you choose?

About to take out a loan for a major investment like your dream home? It can be a jungle to navigate the many loan types - one of them is a FlexLån (FlexLoan).

Read more about how FlexLån® works below.

A FlexLån® helps you finance your dream home or refinance an existing loan. Also known as an adjustable-rate mortgage (rentetilpasningslån), it's a variable-rate loan that doesn't have a fixed interest rate, but is adjusted periodically after an agreed-upon period.

At Bomae, you get financial advisory support that secures you the best and cheapest home loan.

Table of contents:

  • What is an F1, F3, and F5 loan?
  • FlexLoans with and without repayment
  • Pros and cons of F1 loans
  • Pros and cons of F3 loans
  • Pros and cons of the F5 loan
  • Refinancing a FlexLoan
  • How do I choose the right FlexLoan?

What is an F1, F3, and F5 loan? F1, F3, and F5 loans are all adjustable-rate loans. They're typically a type of mortgage loan (realkreditlån) with a variable interest rate. Among other things, this means that the payment on the loan changes with the interest rate, so you don't know the payment amount for the entire term of the loan.

F1, F3, and F5 loans differ primarily in their interest rate adjustment periods. An F1 loan has a 1-year rate adjustment period, F3 has 3 years, and F5 has 5 years, and so on. This means the interest rate is locked in for the given period, and after 1, 3, or 5 years, the loan is refinanced. At that point, the market rate sets the new interest rate.

FlexLån® with and without repayment With a FlexLån®, you have two options: taking the loan with repayment of principal or without repayment of principal (interest-only).

If you choose a FlexLån® with repayment, you pay both interest and principal on the loan every month. This way, the loan balance can decrease over time, since you're paying down the debt through the principal repayment. However, this also means the monthly payment will be higher than on the same loan without repayment.

With a FlexLoan without repayment (interest-only), you only pay the interest on the loan each month. This means your debt won't decrease over time. This type of loan can end up being more expensive overall than an equivalent loan with repayment. In addition, you won't build up equity in the home during the interest-only period. However, you will have a lower monthly payment.

Pros and cons of F1 loans An F1 loan is a type of variable-rate loan where the interest rate is adjusted every year. F1 loans often have a low starting rate, which makes the loan attractive to borrowers who want to pay less interest at the start of the loan.

  • Variable rate An F1 loan is known for its short-term, 1-year rate adjustment period. The loan has a variable rate that changes annually based on market conditions. This can be an advantage if the interest rate is low and expected to fall in the future.
  • Risk of rising rates On the other hand, an F1 loan carries the risk that the interest rate will rise in the future. If the rate rises significantly, your monthly payments can also increase, which can affect your finances. Currently, with rates rising, an F1 loan is, for example, not the cheapest loan.
  • Flexibility An F1 loan gives you the option to refinance or switch to a different loan type after one year. This gives you the flexibility to adjust the loan as needed.

Pros and cons of F3 loans An F3 loan has a longer rate adjustment period of 3 years.

  • Stability F3 loans offer a longer period of stability, since the rate is only adjusted every three years. This can be an advantage, as you have a fixed rate for a longer period.
  • Lower risk An F3 loan carries less risk of rising rates compared to an F1 loan. You have more time to plan your finances and prepare for any rate increases.
  • Less flexibility A downside of the F3 loan is that you're locked into the same loan type for 3 years. This can be a problem if rates fall significantly and you want to refinance the loan.

Pros and cons of the F5 loan An F5 loan has a longer rate adjustment period, which comes with both pros and cons. Here are some important points to keep in mind if you're considering an F5 loan.

  • Long-term planning An F5 loan allows you to plan your finances over the long term. You get more stability and predictability with a fixed rate for 5 years. With a lower monthly payment, there may also be more opportunities to save alongside the loan.
  • Stability and fewer worries With an F5 loan, you don't need to worry about rate increases during the 5 years. If you want even more stability, you could also consider a fixed-rate loan instead.
  • Less flexibility As with the F3 loan, the F5 loan offers less flexibility if interest rates were to fall during the 5 years.

You can choose a FlexLoan with a term of up to 30 years.

Refinancing a FlexLån® Refinancing a FlexLoan means changing the loan to a different loan type, for example a fixed-rate loan. It can also mean switching to a different loan provider if you can get a lower bidragssats (mortgage administration fee). Refinancing a loan between two rate adjustment dates can be an expensive affair - and there may also be other costs associated with refinancing a loan.

Read much more about refinancing a loan here

How do I choose the right FlexLån®? There are several factors you should consider when weighing your choice of loan. These can include:

  • Risk tolerance: If you're willing to take on risk and want lower rates at the start, an F1 loan may suit you. If you prefer more stability, an F3 or F5 loan may be more suitable.
  • Financial planning and budgeting: Also consider how your finances could be affected by rate changes. Do you need predictability, or do you want to plan your finances in the short term?
  • Market conditions: It's also important to consider the current interest rate situation and how rates are expected to develop in the near future. If, for example, rates are expected to rise significantly in the coming years, an F3 or F5 loan can give you more protection against rising rates.

And remember that FlexLån is a registered trademark belonging to Realkredit Danmark A/S - most mortgage credit institutions have their own version and variant of variable-rate loans.

That's why it can be a good idea to consult a financial advisor.

The process for applying for a FlexLoan can vary depending on the specific loan provider. We can help you with that too, at Bomae.

Save time and money

How can we help you? Get a call back today.

Let's have a free chat about your home purchase and financing. We'll contact you within 2 hours on weekdays.