Mixed mortgage: what to check in the fixed and variable phases

A mixed mortgage may seem like a balanced solution because it combines an initial fixed-rate phase with a later variable-rate phase. However, precisely because of that dual structure, it deserves more careful reading than a standard single-rate loan. It is not enough to look at the instalment in the first period: you must understand what will happen when the fixed phase ends, how the variable rate will be reviewed, what costs are included, which fees may apply and what ancillary obligations affect the true cost.

The legal and transparency reference you should bear in mind is Law 5/2019, on real estate credit agreements, and the pre-contractual information in the FEIN, which must clearly show whether the loan has several phases at different rates and how each one behaves. The FEIN also requires risk warnings when the rate is variable and reminds you that, in these cases, the effective APR may differ if the interest rate changes. The legal text itself states that the information must include “the potential risks associated with the interest rate” and, where there are several phases, the conditions for each one BOE, Law 5/2019.

1) What you should check in the fixed phase

The fixed phase is the easiest part to understand, but it can also hide some commercial traps. During this period the instalment does not depend on an index such as Euribor, but that does not mean everything is settled.

1. Check the exact length of the fixed phase.

2. Review whether the instalment includes only capital and interest or whether there are other linked costs.

3. Verify whether there are fees for arrangement, early repayment or partial repayment.

4. Confirm whether you are required to take out linked products to obtain the advertised rate.

At this point, the most common mistake is to look only at the monthly instalment in the fixed phase and forget the overall cost of the linked products or future penalties. It is also common to compare mixed mortgages only on the basis of the first phase without asking what will happen afterwards. If the loan is conditional on salary deposits, insurance or other services, ask for the duration and cost to be set out clearly, because the Law requires these obligations to be stated clearly in the pre-contractual information.

2) What to check before entering the variable phase

The variable phase is what defines the real risk of the mixed mortgage. This is where you need to stop thinking only about the opening instalment and start assessing review scenarios.

1. Identify the reference index that will be used to review the rate.

2. Check the differential applied over that index.

3. Confirm how often the interest rate will be reviewed.

4. Check whether there are caps or floors, and whether there are limits on variation.

5. Analyse whether the FEIN provides an illustrative example of how the instalment could change.

Law 5/2019 and the FEIN require the review formula and its components to be explained clearly. In other words, you should not sign without knowing which index will be used as the reference, what margin the lender adds and when it will be updated. In addition, the documentation must warn that changes in the rate may affect the loan’s effective cost and instalments. If the mortgage is mixed, that warning is especially important because the risk does not appear at the beginning, but when the fixed phase ends.

3) Risk, reviews and not relying on the current Euribor in your decision

You do not need to focus on the “current” Euribor to make a useful decision. In fact, concentrating all your comparison on the index at the time can lead to mistakes. What matters is understanding the review mechanism and the safety margin left by the instalment when the variable phase begins.

In practice, it is worth asking:

1. What would happen if the reference index rises?

2. Would the instalment still be manageable within your monthly budget?

3. Does the loan require you to keep other products throughout the life of the contract?

4. Does the fee for early repayment limit your ability to change strategy if the variable phase becomes expensive?

Practical tip: run your own simulations using several scenarios, not just the most favourable one. Although the FEIN must already include assumptions and warnings, you need to know whether your finances could cope with a rise in the instalment without becoming overstretched.

4) Costs and conditions you should not overlook

A mixed mortgage should not be assessed on interest rate alone. The additional costs and conditions can significantly affect how suitable the product is.

1. Read the FEIN section on “Interest rate and other costs”.

2. Check whether there are one-off costs and recurring costs.

3. Verify whether valuation, registration or certain insurance policies are included or excluded.

4. Ask about the compensation for early repayment and in which phase it applies.

5. Make sure you understand all additional obligations before signing.

The Law regulates early repayment and allows limited compensation in certain cases for variable-rate contracts or variable phases. But that does not mean every mixed mortgage works in the same way: the amount, structure and practical application must be fully described in the loan documentation. You should also check whether the bank makes the more attractive fixed phase conditional on taking out ancillary products that increase the overall cost.

5) Practical steps before signing

Before accepting a mixed mortgage, it is advisable to follow this order:

1. Request the FEIN and read it in full, not just the initial instalment section.

2. Mentally separate the fixed phase and the variable phase.

3. Note the index, differential, review, fees and linked products.

4. Simulate what instalment you would pay if the variable phase rises.

5. Compare the total cost, not just the cheapest opening offer.

6. If anything is unclear, ask for a written explanation before signing.

Common mistake: signing on the assumption that the fixed phase “protects the loan for life”. It does not. Another frequent error is to accept the product simply because the first instalment fits your budget. In a mixed mortgage, the right decision depends on how long the fixed phase lasts, how the variable phase is defined and how much real room the contract leaves you to react.

If you would like to assess a property before buying it or check whether the financing fits your purchase plan, you can request a preliminary estimate at /valoracion-vivienda-madrid. If you would prefer to resolve specific doubts about the purchase or reading the mortgage documents, you can write to us at /contacto. The UBICASA office is at Calle Montesa 29, Madrid, with opening hours Monday to Friday from 10:00 to 15:00 and from 16:00 to 19:00.

In short, with a mixed mortgage you should not look only at the fixed phase or stop at the headline for the variable phase. What matters is checking how the risk changes as you move from one phase to the other, what costs accompany you throughout the contract and whether the pre-contractual information really enables you to understand it.