The single most expensive mistake we see isn't a bad offshore structure. It's a good one, built by someone who forgot their home country charges an exit tax on the way out.

The Ten Mistakes That Cost the Most, Roughly in Order

1. Not addressing the home-country exit tax. Moving from Canada, Australia or a high-tax European country can trigger substantial exit taxes on unrealised gains. One client emigrated from Australia and forgot about CGT Event I1 — a large unrealised gain in the business became taxable at Australian rates the moment they left, not when they eventually sold. Not planning this can cost hundreds of thousands.

2. Setting up an offshore structure without moving personally. Personal residency drives most of the tax outcome, not the entity's address. "I set up a Panama company but stayed a Canadian resident" is the exact sentence behind this mistake: CFC rules apply, the Panama company's income gets attributed straight back, and the owner pays for the setup with none of the tax benefit. A UAE company owned by a Belgian resident is a Belgian tax event, not a UAE one.

3. Underestimating US citizenship-based taxation. US citizens remain fully taxable regardless of where they live. A Panama structure built while remaining a US citizen doesn't produce the tax result most people are hoping for, because the US doesn't tax based on residence in the first place.

4. Ignoring social security contributions. Personal income tax is one line item; social security is another, and countries with 30–40% social security burdens can erase the benefit of an otherwise well-built low-tax structure entirely.

5. Choosing the wrong entity for the operating model. LLC, corporation or partnership isn't a coin flip. Get it wrong and you can pay meaningfully more tax for identical business activity.

6. Building no substance in the low-tax jurisdiction. Post-BEPS, with CFC enforcement tightening, brass-plate companies are the first thing that gets attacked. See Article A26 for what real substance actually requires.

7. Never actually opening the bank account. A beautiful structure with no working bank account is not a functioning structure. See Article A16.

8. Missing VAT or GST obligations. EU VAT and UK VAT are both owed from the first sale, not after some grace period, and missed registrations accumulate fast.

9. Confusing personal and business assets. Commingling in an international structure is a bigger nightmare than commingling domestically, because now two tax authorities are looking at the same mess. Separate cleanly from day one.

10. Getting the timing wrong. One client sold their SaaS business three months after moving to Puerto Rico, expecting the 4% Act 60 rate. A substantial part of the gain was attributed to the pre-Puerto Rico period instead, and the actual result looked nothing like what they'd planned for. Moving countries in December instead of January, or selling in one fiscal year instead of the next, can double or halve a tax bill on its own.

The Common Root Cause

Nearly all of these trace back to the same root: advice from someone who understands only one side of the move. One client moved to Portugal under NHR but kept everything structured through the UK — NHR's benefits depend on Portuguese source rules lining up correctly, and poor structuring wasted the regime almost entirely. Their UK adviser knew the UK side. Nobody on the team understood how Portugal would actually treat it.

Cross-border planning needs someone with genuine visibility into both the country you're leaving and the one you're arriving in, not two separate advisers each confident about half the picture.

Getting the Sequencing Right

Most of these mistakes are avoidable with the right sequencing, and sequencing is exactly what gets skipped when the move happens before the plan does. On a scoping call, FTR walks through your restructuring plan before you've moved, not after, checking it against exit tax, CFC exposure and timing. Bring your target country and rough timeline, and you'll leave with the order of operations that avoids the ten mistakes above. Book one here.

General information, not personal tax or legal advice. Every one of the cases above turned on specific facts — get advice on yours before you restructure anything.