A common sales pitch: "Vietnamese passport gets you into 52 countries, Caribbean passport gets you 145 countries, add them together and you get nearly 200."
That math is wrong—and wrong in favor of the seller.
Why You Can't Simply Add Them
The two passports overlap significantly. Most countries that grant visa-free entry to a Vietnamese passport also grant it to a Caribbean passport—Southeast Asia, numerous island nations, and several South American countries appear on both lists.
The correct calculation uses the union of two sets, not simple addition:
Actual Total = A + B − overlap
The overlap is usually substantial. With a Vietnamese passport paired with a Caribbean passport, the overlap can account for thirty to forty destinations. This means simple addition inflates the figure by dozens of countries.
The Number That Actually Matters
The question to ask is not "how many do I get if I add them," but "how many additional countries do I gain, and which ones are they?"
Take the Vietnamese passport as an example:
Adding a Caribbean passport typically opens the Schengen area, the United Kingdom, and numerous other European countries, plus many destinations in South America and Africa. This addition has real value because it includes places unavailable on the Vietnamese passport alone.
Adding another Southeast Asian passport adds almost nothing, because the overlap with the Vietnamese passport is too great.
Same action—"add one more passport"—but vastly different value.
Three Things the Total Number Won't Tell You
The United States is not part of what a Caribbean passport adds. No Caribbean passport grants visa-free entry to the United States. What a Grenada passport offers regarding the United States is eligibility to apply for an E-2 visa—an investor visa under a bilateral trade agreement that Vietnam does not have a comparable arrangement for. That is real value, but it is something different from visa-free travel.
China is a notable exception. Some Caribbean passports have visa-free agreements with China, which the Vietnamese passport does not.
Visa-free entry is not the same as the right to live and work. A Caribbean passport grants short-term visa-free access to the Schengen area, typically 90 days within 180 days. It does not grant the right to live and work in European Union countries. Many buyers discover this only after purchasing.
Vietnamese Law on Dual Citizenship
The most common question: do I have to renounce Vietnamese citizenship?
Vietnamese nationality law follows the principle of single nationality but allows dual citizenship in certain circumstances. In practice, many Vietnamese citizens do hold both.
We recommend you consult a lawyer specializing in Vietnamese law on this point, not an immigration consultant. Individual situations vary, and the implications for civil registration, inheritance, and military service obligations for your children are real legal matters. We are not a law firm and cannot offer legal opinions.
How to Calculate for Your Own Situation
Step 1 — list the countries you genuinely plan to visit over the next three years. The real number is usually between five and fifteen.
Step 2 — for each country, check your current passport tier: visa-free, visa on arrival, ETA, e-visa, or advance visa required.
Step 3 — repeat Step 2 with the passport you are considering.
Step 4 — count the countries that move from "visa required in advance" to "visa-free." That is the true value of the second passport for you.
If the number in Step 4 is two or three countries, then hundreds of thousands of dollars is expensive. If it is fifteen countries, and several of them are places you visit regularly for work, the calculation changes entirely.
We offer a passport comparison tool to automate Steps 3 and 4. But Step 1 you must do yourself—and it is the most important step.