Investing
How to Calculate Cash Flow on a Spanish Rental Property
Cash flow asks a simpler question than yield: how much money is left after the property's costs and loan payments? Using one hypothetical Costa del Sol example, this guide builds the figure step by step and stress-tests it.
Published · 4 min read
By Costa de Oro · Real-estate agency · Marbella & Costa del Sol
Cash flow is not yield and not taxable profit
Yield compares income with capital. Cash flow tracks money in and out of your account over a period. A property can show a reasonable net operating yield and still leave little cash once a mortgage is paid.
Taxable profit is different again. For tax purposes, interest and certain costs may be deductible while principal repayment is not, depreciation is a non-cash allowance, and capital improvements are treated differently from repairs. Rules also differ for residents and non-residents, so the cash result should not be used as a tax figure.
Step 1: from rent to net operating income
The example is hypothetical: a €200,000 apartment with €25,000 of illustrative transaction and setup costs, let at €1,200 a month. It is not market data or a promised result.
- Scheduled rent: €1,200 × 12 = €14,400
- Less one vacant month: €13,200 collected, assuming remaining rent is paid
- Less operating costs: IBI €600, community €1,200, insurance €300, maintenance €600, management €900 = €3,600
- Net operating income (NOI): €9,600 a year
Step 2: subtract debt service
Assume an illustrative €140,000 mortgage with annual debt service of €8,400, covering both principal and interest. This is not a lender quote and no interest rate or term is implied. For a variable-rate loan, use the lender's actual amortisation schedule and repricing terms.
Formula: before-income-tax cash flow = NOI − annual debt service. Here, €9,600 − €8,400 = €1,200 a year, or €100 a month on average. The word average matters: real months will vary.
Step 3: reserves and monthly timing
Set aside a replacement reserve for items that wear out, such as appliances or air conditioning. In the example, a €600 annual reserve leaves €600 a year of available cash, or €50 a month on average. The reserve is money set aside, not an actual expense, and is not automatically tax-deductible. When a funded repair is later paid from it, do not count the cost again.
Build the forecast month by month. IBI, insurance and community levies may be charged annually or in instalments, so some months will be negative even when the year is positive. The tenant's deposit is held against obligations and is not rental profit.
Step 4: stress-test the result
Change one assumption at a time with operating costs held fixed, then combine them. Do not deduct the same vacancy twice.
- Extra vacant month: income falls by €1,200 → €0 before reserve, −€600 after reserve
- Debt service €100 a month higher: +€1,200 a year → €0 before reserve, −€600 after reserve
- Both together: −€1,200 before reserve, −€1,800 after reserve
- Short-term model: lawful bookable nights × occupancy × realised nightly rent, minus platform, management, cleaning and utilities, each counted once
A cash-flow checklist
Verify that the intended rental use is permitted, including community rules and any tourist-rental requirements, before building income on it. Confirm current rules at the time of purchase; they change.
Keep the tax calculation separate and ask an adviser which costs are deductible in your situation.
- Monthly schedule for 12–24 months, not only an annual total
- Actual IBI, community and insurance charges and their payment dates
- Loan schedule showing principal and interest separately
- Replacement reserve and working cash buffer defined
- Stress cases for vacancy, rate changes and one-off repairs
- Tax estimate prepared separately by a qualified adviser
Common questions
Why is my cash flow lower than the net yield suggests?
Net operating yield is before financing. Loan payments, including principal, reduce the cash you receive even though principal builds equity.
Is the replacement reserve an expense?
Not when you set it aside. It is a cash-planning allocation. The actual repair becomes a cost when paid, and you should not count it twice.
Can I use cash flow for my tax return?
No. Taxable rental income follows separate rules on interest, depreciation, repairs and improvements, and differs by residency. Use a qualified tax adviser.
