Mortgage Comparator: How to Compare Two Offers and Pick the Better One
A mortgage comparison tool does more than show monthly payments side by side. Done properly, it models the total cost of each loan over its full life, including fees, linked-product costs, and the sensitivity of variable-rate options to future interest rate scenarios. This guide explains what to compare, how to read the numbers, and which tools give you genuinely independent data in 2026.
Why TIN Is Not Enough: Compare TAE
The most common error when comparing mortgages is comparing TIN (Tipo de Interés Nominal, the nominal rate) without accounting for total cost. Two mortgages can have identical TINs and very different TAEs (Tasa Anual Equivalente — the Spanish equivalent of APR):
- Mortgage A: TIN 3.20%, no opening fee, no linked insurance requirement → TAE ≈ 3.25%
- Mortgage B: TIN 3.10%, 1.0% opening fee (EUR 2,000 on EUR 200k), mandatory life insurance EUR 600/year → TAE ≈ 3.55%
Mortgage B has a lower TIN but costs significantly more over 25 years. Under Ley 5/2019 (Ley Hipotecaria), all Spanish lenders must disclose the full TAE in the FEIN (Ficha Europea de Información Normalizada) document. This is the legally binding comparison metric.
The Five Variables That Matter in a Side-by-Side Comparison
When evaluating two mortgage offers, build a comparison table across these five dimensions:
| Variable | What it means | Where to find it |
|---|---|---|
| TAE | Full annual cost including all mandatory charges | FEIN, page 2 |
| Total interest over full term | Sum of all interest payments | FEIN amortization schedule |
| Comisión de apertura | Upfront fee at signing | FEIN, section 4 |
| Linked products (vinculaciones) | Insurance, accounts, cards required | FEIN, section 10 |
| Early repayment fee | Penalty for prepaying | FEIN, section 12 |
Monthly payment is useful for cash-flow planning, but it is a secondary metric — focus on total cost and TAE first.
Worked Example: EUR 200,000 / 25 Years — Comparing Five Banks
Using representative 2026 market data (verify current FEINs before acting):
| Lender | TIN (fixed, bonificado) | Opening fee | Linked products cost/year | Estimated TAE | Monthly payment |
|---|---|---|---|---|---|
| ING Naranja | 3.45% | EUR 0 | EUR 650 (insurance) | 3.72% | EUR 992 |
| Openbank | 3.30% | EUR 0 | EUR 700 (insurance + payroll) | 3.61% | EUR 978 |
| EVO Banco | 3.35% | EUR 0 | EUR 580 (home insurance) | 3.61% | EUR 984 |
| BBVA (standard) | 3.55% | EUR 0–800 | EUR 750 (insurance bundle) | 3.84% | EUR 998 |
| Sabadell | 3.70% | EUR 1,200 | EUR 900 (5 linked products) | 4.12% | EUR 1,010 |
Key observation: The difference between the best (Openbank, 3.61% TAE) and worst (Sabadell, 4.12% TAE) options on EUR 200k/25 years translates to approximately EUR 18,000–EUR 22,000 in total additional interest over the life of the loan. This is the value of proper comparison.
How to Compare a Fixed vs a Variable Mortgage
Fixed vs variable comparison requires scenario modeling because the variable rate’s future cost is unknown. A three-scenario analysis is the standard approach:
Loan: EUR 200,000 / 25 years
- Fixed: 3.50% TIN throughout
- Variable: EURIBOR 12M + 0.85% (EURIBOR currently at 2.45% → effective 3.30% in year 1)
| EURIBOR scenario | Variable effective rate | Variable monthly payment (approx.) | Fixed monthly payment |
|---|---|---|---|
| Current (2.45%) | 3.30% | EUR 974 | EUR 1,001 |
| +1.5pp (3.95%) | 4.80% | EUR 1,143 | EUR 1,001 |
| +3.0pp (5.45%) | 6.30% | EUR 1,321 | EUR 1,001 |
| −1.0pp (1.45%) | 2.30% | EUR 870 | EUR 1,001 |
The fixed mortgage becomes cheaper in total cost if EURIBOR averages above approximately 3.0%–3.5% over the full 25-year term. Given ECB rate uncertainty, this is a personal risk tolerance decision rather than a pure math problem.
What Changes When Term Changes
Extending the term lowers monthly payments but raises total interest significantly:
Loan: EUR 200,000 at 3.50% fixed
| Term | Monthly payment | Total interest | Total cost |
|---|---|---|---|
| 15 years | EUR 1,430 | EUR 57,400 | EUR 257,400 |
| 20 years | EUR 1,160 | EUR 78,400 | EUR 278,400 |
| 25 years | EUR 1,001 | EUR 100,300 | EUR 300,300 |
| 30 years | EUR 898 | EUR 123,200 | EUR 323,200 |
Going from 20 to 30 years saves EUR 262/month but costs an additional EUR 44,800 in total interest. For many borrowers, the monthly payment reduction is worth it — but the comparison should be made consciously.
Leading Independent Mortgage Comparators in Spain (2026)
| Platform | Type | How they work | Revenue model |
|---|---|---|---|
| Helpmycash | Broker-assisted | Rate tables updated by editorial team weekly; can negotiate on your behalf | Referral fee from lender if you sign |
| Idealista Hipotecas | Broker-assisted | Part of major real estate portal; good for purchase + mortgage bundle | Referral fee |
| iAhorro | Broker-assisted | Large network; proactively contacts multiple lenders | Referral fee |
| Rastreator | Aggregator | Primarily insurance; limited mortgage depth | Lead generation |
| Simúlalo | Independent calculator | Amortization math, no lead capture | No commercial relationship with lenders |
Important: Broker-assisted comparators are useful for rate negotiation but are compensated by lenders, which creates selection bias — they may not show lenders who do not pay referral fees. Verify any shortlist against direct lender FEINs.
Red Flags in Mortgage Comparators
- Sponsored placements. Some comparators list certain banks first not because they are cheapest, but because they pay a higher referral fee. Always sort by TAE, not by default ranking.
- Rates not verified by date. Mortgage rates change frequently. A comparator last updated 3 weeks ago may show rates that no longer exist. Always confirm with the lender directly.
- Free simulations that capture your lead. Some "free calculators" require your phone number and immediately forward your data to bank sales teams. Read the terms before entering personal information.
- Missing linked-product cost in comparison. A comparison that shows TIN but not vinculaciones cost is not a full comparison. Make sure the tool accounts for insurance and other required products.
- FEIN delivery delays. Under Ley 5/2019, lenders must provide the FEIN at least 10 business days before signing. If a lender delays or makes the FEIN hard to obtain, that is a compliance signal worth noting.
How to Run Your Own Comparison in Four Steps
- Identify your parameters. Fix the loan amount, term, and LTV you need. Run the same parameters through all lenders.
- Request FEINs from at least 3 lenders. This is a legal right under Ley 5/2019. You do not need to be a client to receive a FEIN.
- Compare TAE and total interest, not just monthly payment. Build a simple spreadsheet with the outputs from each FEIN.
- Model the EURIBOR scenarios for variable offers. Use three rates: current, +2pp, +4pp. This gives a realistic range of outcomes.
A mortgage is typically the largest financial obligation in a lifetime. Spending 2–3 hours on a structured comparison across 3–4 lenders is consistently one of the highest-return uses of time in personal finance.