Why San Marino Never Joined the EU That Surrounds It
San Marino has run a customs union with Brussels since 1991 and uses the euro, but two referendums on full EU membership have both failed, the second on a turnout technicality.
Drive out of Rimini on Italy's Adriatic coast, climb about 20 minutes into the hills, and you cross a border with no checkpoint, no passport stamp and, since 301 A.D. by its own founding legend, no Italian sovereignty at all. San Marino is a sovereign country the size of a mid-sized American town, wrapped entirely inside a single European Union member state — and after more than three decades of on-and-off talks, it still isn't part of the EU that surrounds it.
The holdout isn't stubbornness for its own sake. It's arithmetic, and San Marino has looked at the numbers twice, formally, and both times decided against it. It's a milder version of a puzzle that shows up across the continent in stranger forms — Kaliningrad's total encirclement by NATO and the EU, or Transnistria's decades in sovereignty limbo — except San Marino's isolation is entirely its own choice, revisited and reaffirmed at the ballot box.
The smallest voter in the room
San Marino has roughly 34,000 residents. Malta and Luxembourg, the EU's current smallest members, each hold six seats in the European Parliament despite populations in the hundreds of thousands — giving a Maltese or Luxembourgish voter something like ten times the per-person representation of a German one. Extend that same logic to a country of 34,000, and the imbalance stops looking like an edge case and starts looking like a structural problem the European Commission itself has flagged. When Brussels evaluated membership options for San Marino, Andorra and Monaco in 2012, it concluded plainly that "the EU institutions are currently not adapted to the accession of such small-sized countries," and ruled out full membership as a near-term option.
That verdict didn't end the conversation domestically. It just moved it to the ballot box.
Two referendums, two rejections
In 2011, a campaign gathered enough signatures to force a national referendum on applying for EU membership. It never happened — the government preempted it by sending Brussels a formal letter requesting "greater integration," and Sammarinese election authorities accepted that as satisfying the demand and canceled the vote.
Backers tried again. A second referendum, this one asking voters directly whether San Marino should apply for full EU membership, was held on Oct. 20, 2013. A majority of those who voted said yes. It didn't matter: San Marino requires 32% of all registered voters to participate for a referendum result to count, and turnout fell short of that quorum. The measure failed on a technicality that was really a statement — enough Sammarinese wanted membership to win a majority of ballots cast, but not enough treated the question as urgent enough to show up.
What San Marino has instead
None of this leaves San Marino outside the EU's economic orbit. It has run a customs union with the bloc since 1991, extended to agricultural goods in 2002. It uses the euro as its sole currency under a monetary agreement, and is even permitted to mint a small allotment of its own commemorative coins each year. Sammarinese residents cross into the Schengen Area freely, despite the country never having formally joined Schengen itself, with only occasional police spot checks at the border.
| Arrangement | Status |
|---|---|
| Customs union with the EU | In force since 1991 (agriculture added 2002) |
| Currency | Euro, via monetary agreement; mints own coins |
| Schengen Area | Open border, not a formal member |
| Full EU membership | Rejected by referendum quorum failure, 2013 |
| Association Agreement | Negotiations concluded Dec. 2023; still pending ratification |
The current negotiating track, alongside Andorra, is a multilateral Association Agreement rather than membership — a deal designed to fold San Marino more tightly into the EU's internal market without giving it a seat at the table where EU law gets written. The European Commission announced the conclusion of those negotiations in December 2023 and formally proposed the deal to the Council of the European Union in April 2024. It still isn't in force. In December 2025, the Council determined the agreement touches policy areas that fall partly under national rather than purely EU authority, meaning it now needs ratification in the parliaments of all 27 EU member states before it can take effect — a process with no fixed end date.
Sammarinese politics remains split roughly along the same lines it was in 2013. The governing Christian Democratic Party has stayed neutral to skeptical on full membership; smaller opposition parties, including the United Left coalition, have consistently backed it. Neither side has enough momentum to force the question back to voters, and Brussels, for its part, has shown no appetite to revisit full membership for a country whose population is smaller than a single European Parliament constituency. For now, San Marino keeps the euro, the open border and the customs union — everything but the vote.
