About
Built from inside the Spanish tax system.
For investors buying from outside it. A boutique advisory in Torrevieja: we analyse property investments for foreign buyers, partner with Costa Blanca landowners on turnkey development projects, and handle the legal, tax and administrative side of the purchase.
Why we exist
No one was protecting the buyer.
Buying property in Spain as a foreign investor can be a very good decision. It can also be the most expensive mistake of your life. Taxes, hidden debts, planning restrictions, community liabilities, tourist licensing and reporting obligations: none of them appear in the listing, and few are mentioned at the viewing.
Our co-founder, Sarah Katerina Kastlunger Pérez, spent 20 years as a Senior Director at SUMA Gestión Tributaria, the tax authority of the Province of Alicante. From inside, she saw the patterns the market never advertised, repeating across thousands of transactions.
Advisors came from sales, and their incentives pointed the wrong way. The investor, usually from abroad and often working in a second language, was the last person in the room to see the full picture. Costa Larga was built to change that.
What makes us different
Four commitments.
We work on both sides of the market
Private foreign investors on one side, major Costa Blanca landowners on the other. That lets us structure turnkey development projects with the people who control the land and bring them to investors before the open market.
Every opportunity has a written case
Not a brochure. A one-page memo with real assumptions, rental income, running costs, tax, financing and exit. If a project cannot be defended on that page, it does not reach your desk.
We are comfortable saying no
Our most valuable answer is often "don't buy this one". When the numbers do not work or the tax position is not clean, we say so plainly.
We see the purchase through
NIE, Spanish bank account, notary, taxes and registration in the Registro de la Propiedad. You sign; we run the process.
Who we work with
Private investors, mainly from the UK, Scandinavia, the Netherlands, Germany and the rest of Europe, who treat Spanish property as an investment decision rather than a holiday impulse. Typically they:
- are considering a first or second purchase in Spain
- prefer structured analysis to a sales pitch
- want the real numbers before committing capital
- value legal clarity, tax transparency and professional coordination
Why only here
We work in Torrevieja and the surrounding Costa Blanca because it is the market we know from the inside: every town, every community, every notary.
That local depth lets us underwrite honestly. The difference between a strong investment and a disappointing one rarely shows up in the photos. It shows up in the paperwork.
Team
The people behind the reports.
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Sarah Katerina Kastlunger Pérez
CEO and co-founder. Former Senior Director at SUMA Gestión Tributaria
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Igor Kastlunger
Partner. Investment structuring and rental operations
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Angelica Bernal Pico
Client advisory
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Elsa Quirós Pérez
Acquisitions, Torrevieja and Costa Blanca
Start here
Talk to us before you commit.
Bring us the property you are looking at, or just the strategy you are considering. We will tell you what the numbers say, what the risks are, and whether it deserves your capital.