Nominal rate (TIN) vs APR (TAE) on a mortgage

Practical guide · Last regulatory check:
Legislation and case law checked as at 13 June 2026. This page is not updated automatically. Check the current official sources before acting. The worked figures are hypothetical and do not represent market prices.

The difference between the TIN (nominal rate) and the TAE (APR) on a Spanish mortgage is that the nominal rate calculates the payment, while the APR adds compounding and linked costs. That is why two loans with the same interest rate can cost differently, as the 3.00% example shows.

What is the TIN (nominal rate)?

The TIN (Tipo de Interés Nominal, the nominal interest rate) is the percentage the bank applies to your outstanding capital to work out the interest. It is the number used directly in the monthly payment formula of the French repayment system (the one this calculator uses):

payment = C · i / (1 − (1 + i)−n)

Where C is the capital, i is the nominal rate divided by 12 (the monthly rate) and n is the number of months. On its own, the nominal rate includes no costs: no fees, no insurance, not even how often interest is charged. That is why it is an incomplete figure for comparing offers.

What is the TAE (APR)?

The TAE (Tasa Anual Equivalente) is Spain's APRC (Annual Percentage Rate of Charge; commonly called APR), a measure designed precisely for comparison. It reflects the real annual cost of the loan because it incorporates three things the nominal rate ignores:

By construction, in this calculation (with monthly compounding) the APR is normally equal to or higher than the nominal rate. If a mortgage had no costs at all, its APR would be only slightly above the nominal rate (because of monthly compounding). As soon as you add fees or linked insurance, the APR rises and pulls away from the nominal rate.

Why does the APR matter when comparing?

The APR matters when comparing because it gathers in one percentage the cost the nominal rate does not show. Imagine two mortgages advertised with the same nominal rate: at first glance they look identical, but one might carry an arrangement fee of several hundred euros and require linked insurance, while the other carries nothing. The monthly payment of the "pure" mortgage will be the same in both (it depends only on the nominal rate), but the total cost will not.

The APR captures that difference in a single number: when two offers have a similar nominal rate, a lower APR points to lower cost.

Be careful, though, comparing the APR between loans of very different amounts or terms: the APR is a rate, not an amount. For big decisions it is also worth looking at the total cost in euros over the whole life of the loan, not just the percentage.

How can the APR change with the same nominal rate?

The APR can change with the same nominal rate when one mortgage includes countable costs and the other does not. In the example, two loans with a 3.00% nominal rate keep the same €711.32/month payment, but not the same effective cost.

Purely hypothetical example, checked on 13 June 2026. The amounts, rates, fees and insurance were chosen to explain the method; they do not represent market prices or offers.

Let's see it with figures. We start with two mortgages identical in the essentials:

With the French formula, the monthly rate is 3.00% / 12 = 0.25%. The payment comes out the same in both mortgages, because the nominal rate is the same:

payment = 150,000 · 0.0025 / (1 − 1.0025−300) ≈ €711.32/month

Over 25 years you pay 300 instalments. The exact total is €213,395.09 (of which €63,395.09 is interest), calculated with the unrounded payment of €711.31697; multiplying the already-rounded payment (€711.32 × 300) would give €213,396, a difference due only to rounding. Up to here, the two mortgages are indistinguishable. The difference is in the costs:

The APR is found by looking for the rate that equals the money you actually receive with all the payments you actually make. In mortgage A you receive the full €150,000 and only pay the instalments; in B, the arrangement fee reduces the net capital received to €148,500 and each year the insurance is added to the payments. The result, calculated with the comparison tool, is:

ItemMortgage A (no costs)Mortgage B (with costs)
Nominal rate3.00%3.00%
Monthly payment€711.32€711.32
Arrangement fee€0€1,500
Linked insurance (countable)€0€300/yr (€7,500 over 25 yrs)
Approximate APR3.04%3.47%

Same 3.00% nominal rate and yet the APR jumps from 3.04% to 3.47%: almost half a point of difference that the nominal rate, on its own, was hiding from you. Translated into euros, mortgage B costs you the €1,500 arrangement fee plus €7,500 of insurance over the loan: around €9,000 extra that the monthly payment does not reflect. That is why mortgage A's APR is the signal that it is the cheaper option, even though the advertised nominal rate was identical.

Calculation note: the 3.47% APR assumes the linked insurance is charged with the payments of months 1, 13, 25, …, 289 (that is, at the end of those months), once for each of the 25 annuities. When working out the APR of a real contract, the actual charging dates of each cost should be used, which may change the result slightly.

Compare the payment and the APR with our calculator

Which costs count towards the APRC and which do not?

The costs that count towards the APRC are those forming part of the total cost of the credit; costs paid outside the loan or excluded by law stay out.

Not every mortgage cost is included in the APRC (TAE). The ones that count form part of the total cost of the credit: those that are a condition for obtaining the loan or part of its price (Article 4 of Law 5/2019).

Because the line depends on the specific terms of each offer, the practical approach is to decide case by case which cost you mark as countable. To see the exact effect in your case, you can enter your own costs in the calculator and tick individually which ones count towards the APR.

Frequently asked questions

What is the nominal rate used for on a mortgage?

The nominal rate on a mortgage is used to calculate the monthly capital-and-interest payment. It is the percentage the bank applies to the outstanding capital and, in the French repayment system, it is divided by 12 to obtain the monthly rate used in the payment formula.

Why can two mortgages with the same nominal rate have different APRs?

Two mortgages with the same nominal rate can have different APRs because the APR includes costs the nominal rate does not reflect. In the example, both have a 3.00% nominal rate and a €711.32 monthly payment, but mortgage B adds a €1,500 arrangement fee and €300 per year of linked insurance.

Which costs should you review when looking at the APR?

When looking at the APR, review the costs that form part of the total cost of the credit: the arrangement fee, linked insurance required as a condition of the loan, and the valuation when it is necessary to obtain the credit. Costs outside the loan, voluntary insurance and taxes for registering the transfer of ownership are excluded.

Should you also look at euros as well as the APR?

Yes. The APR is a rate, not an amount, so for big decisions it is worth reviewing the total cost in euros over the whole life of the loan. In the example, mortgage B adds about €9,000 through the arrangement fee and linked insurance.

Summary

Official sources

Notice: this guide and the calculator are for information and educational purposes. They are not financial advice or a loan offer. The calculations are indicative estimates; your bank may apply different rounding, fees or linked products. Before taking out a mortgage, check the lender's official terms and, if needed, an independent financial adviser.

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