The advertised cost-of-living index is what gets people moving abroad: "Lisbon is 40% cheaper than San Francisco." Sometimes that's true. Often it's a partial truth that omits four costs which don't show up in the headline number. Done right, the math can still favor relocation. Done wrong, it can leave you worse off than you started.
Why headline cost-of-living numbers can mislead
Cost-of-living indices are typically built from rent, groceries, transport, and entertainment in a major city. They don't include international health insurance for non-residents, the tax filings you may still owe to your home country, banking and currency frictions, or the one-time costs of actually getting set up. Those four categories — insurance, taxes, banking, setup — can shift the picture by hundreds of dollars per month, or more.
The Digital Nomad Calculator takes the recurring monthly costs into account, but the four hidden costs are worth understanding separately because they often catch people off guard during the first year.
Hidden cost #1: International health insurance
Domestic insurance from your home country usually doesn't cover you long-term abroad. Travel insurance is fine for trips, but it's not designed to be your primary coverage for months or years. International health insurance (sometimes called expat insurance or global medical insurance) fills that gap.
Premiums depend on age, family size, geographic coverage area, and the deductible. A common range for a single nomad in their 30s with global coverage (excluding the US, where premiums spike) is roughly $80–$200 per month for a basic plan. Coverage that includes the US, family plans, and pre-existing conditions can be substantially higher. The Nomad Health Insurance Estimator can model your specific case.
This cost is real and recurring. Build it into your monthly budget abroad before comparing.
Hidden cost #2: Tax filings you may still owe
This is the one most people miss. Some countries (the United States is the well-known case) tax their citizens on worldwide income regardless of where they live. Living abroad doesn't end the filing obligation. The Foreign Earned Income Exclusion can reduce or eliminate the actual tax owed in many cases, but the filing still has to happen, and it often costs money to prepare correctly.
Other countries operate on residency-based taxation: leave, become non-resident properly, and your filing obligation in the home country largely ends. The rules around how to qualify as non-resident vary widely and are usually more demanding than people expect.
On the destination side, you may also become liable for local income tax depending on how long you stay, whether you have a permanent home in the country, and other tests. The Tax Residency Checker screens for the most common triggers, but the answer is rarely straightforward and is one of the strongest arguments for talking to a cross-border tax professional before a long-term move.
Hidden cost #3: Banking and currency
Banking abroad is rarely as smooth as banking at home. The friction shows up in several places:
- Foreign transaction fees. Using a card from your home country abroad often charges 1–3% per transaction. Over a year of monthly spending, this adds up.
- ATM and currency exchange. Even with a fee-free debit card, exchange rates from one currency to another carry hidden margins. Specialist services (multi-currency accounts and transfer services) reduce this but require some setup.
- Local bank account access. Opening a local account often requires a residence permit or proof of address, which you may not have until you've been there a while.
None of these are dealbreakers. They do add a couple of percentage points of friction to your effective spending, especially in the first few months.
Hidden cost #4: One-time setup
The first move abroad has costs you don't repeat. Common items:
- Flights for you and your family.
- Visa application fees, often per person.
- Apartment deposits — typically one to three months of rent depending on country.
- Moving belongings or buying replacements once there.
- Registration with local authorities, where required.
- A buffer for the first month or two while you find your footing.
Add it all up and a single nomad's setup can easily run several thousand dollars; a family's can run substantially more. Spread that over your expected stay to get a per-month equivalent — or use the Break-Even Savings Calculator to see how long the monthly savings need to last to recover the setup.
What the real comparison should include
Once you have the four hidden costs estimated, the comparison becomes more honest. Build a monthly figure that includes:
- Recurring living costs abroad (rent, food, internet, transport, coworking).
- International health insurance.
- Estimated additional tax cost (or estimated tax savings, if applicable).
- Banking and currency friction (estimate as a percentage of monthly spend).
- Amortized one-time setup costs (total setup divided by how many months you expect to stay).
Compare that total to your current monthly cost at home. The honest comparison is rarely the headline 40% saving — it's often closer to 15–25% in genuinely cheaper cities, less than that in popular ones, and occasionally negative in places with high private health costs or strict tax-residency rules. To compare destinations side by side, the Cost of Living Comparison can help once you have these numbers in hand.
What this won't tell you
This guide is about the math. It doesn't address the harder questions that often matter more: whether you have the visa to actually live somewhere, whether the climate or community fits, whether your work continues to function across time zones, whether your family's medical or educational needs are met locally. These questions can decide a relocation more than the cost difference does.
A move abroad that loses you $200 a month but suits your life can be the right call. A move abroad that saves you $200 a month but doesn't can be the wrong one. The math is the floor of the analysis, not the ceiling.
This is an educational guide, not personalized financial, tax, or legal advice.