I have supported dozens of expats in recent years, and I have watched the same mistakes repeat themselves, again and again. Mistakes that do not necessarily ruin a life, but that turn a great adventure into an administrative, financial, or emotional ordeal. Some of them I made myself. Others were told to me with that mix of shame and retrospective humor reserved for lessons learned the hard way.

Here are the 7 mistakes I see most often, and how to avoid them.

1. Not Changing Your Tax Residency Correctly

This is the number one mistake, by far. You leave, you open a bank account abroad, you rent an apartment, you work from Lisbon or Bangkok… and you continue filing your taxes in France, sometimes out of habit, sometimes out of fear, sometimes out of ignorance.

The problem: your home country does not let go of you that easily. Most tax systems (see the PwC Worldwide Tax Summaries on individual tax residency) consider you a tax resident as long as your household, your principal place of activity, or your center of economic interests remains there. Leaving without officially cutting these ties means risking a tax reassessment years later.

What to do: close unnecessary accounts in France, report your change of address to the tax authorities, keep proof of residence abroad (lease, utility bills, employment contract), and if possible obtain a tax residence certificate in your host country.

2. Keeping Your Auto-Entrepreneur Status

I have seen people live in Dubai for two years while keeping their French micro-enterprise, convinced it simplified things. It simplifies nothing. On the contrary, it creates potential double taxation, an artificial link with France, and a situation that is difficult to explain to the administration.

The auto-entrepreneur status is designed for activities carried out from France. If you leave, you should in principle deregister it and create a structure suited to your host country or your business model. Alternatives are plentiful depending on your destination: local company, freelance status, international payroll services.

3. Underestimating Loneliness

I have been told this story several times, with variations: the first week is euphoric. The second month is strange. By the third month, you are crying watching a video of the bakery in your old neighborhood.

Expat loneliness is real, predictable, and rarely anticipated. You leave surrounded by the excitement of the project, you arrive in a country where nobody knows you, where social codes are different, where making friends at 35 takes deliberate effort. This is not a weakness. It is the normal condition of an expat in the settling-in phase.

What to do before leaving: identify communities (Meetup, Facebook expat groups, co-working spaces), set aside a “social life” budget for the first months, and do not isolate yourself in the apartment waiting for friends to come to you.

4. Not Testing the Country Before Giving Up Everything

I have seen people sell their apartment, leave their permanent job, move all their belongings, only to realize three months later that the chosen country did not suit them at all. That it was too hot. That the language was an insurmountable barrier. That the pace of life did not match what they had imagined.

A two-week tourist trip does not tell you how you will live there. What you need is at least a one- to three-month stay in “local living” mode: rent an apartment, cook, do the grocery shopping, use public transportation, work from cafes or co-working spaces. This is a modest investment compared to the cost of a failed expatriation.

Destinations like Portugal or Thailand lend themselves particularly well to this test. You can discover how to move to Portugal or how to move to Thailand to prepare a trial stay under the best conditions.

5. Ignoring Health Coverage

Your home country’s public health system typically does not follow you abroad, at least not indefinitely. Some countries offer voluntary affiliation schemes for expatriates, and the European Commission’s guide for citizens living abroad covers EU cross-border healthcare rights. These options are often paid and not suited to all profiles.

I have seen people leave without any international coverage, convinced they were young and healthy. Until the day there was an emergency hospitalization costing 8,000 euros. Or a medical evacuation costing 30,000 euros.

International health insurance (such as Cigna or comparable) costs between 80 and 200 euros per month depending on your age and level of coverage. It is non-negotiable.

6. Romanticizing the Destination

Instagram lies. Travel blogs lie. Or rather: they show the idealized version of a reality that also has its less photogenic aspects.

Bali is also power outages, visa issues, administrative corruption, stifling heat six months a year, and difficulties opening a bank account as a foreigner. Dubai is also the absence of organic social life, culture shock, and the difficulty of integrating in a transient city.

This is not to discourage, it is to calibrate expectations. Read testimonials from expats who have been living in your target country for more than two years, not digital nomads on a six-month stay.

7. Making the Decision in a Rush

An expatriation decided after a bout of blues, a workplace conflict, a breakup, or a heated discussion about taxes is rarely the best-prepared expatriation. And a poorly prepared expatriation often means a rushed return to France, with your tail between your legs and your finances damaged.

The decision to leave deserves at least six months of serious consideration: choice of country, tax strategy, professional status, health coverage, housing, local network. This is not procrastination; it is preparation.

These mistakes have one thing in common: they all stem from a lack of information or insufficient preparation. None is irreparable, but some are costly, in money, energy, and time. Expatriation is a great decision. It deserves to be made with eyes wide open.