378 Country Code: San Marino (+378)

Most failed calls to San Marino come from one of four mistakes, not from network problems. The most common is mishandling the country code itself: San Marino uses +378 with no trunk prefix to remove, so you dial it as-is. The most frequent error is adding a leading 0 by habit — there is none in the San Marino number plan.

The second is misreading the area code on landline numbers — San Marino numbers may have variable formatting depending on the carrier and city, so confirm the area code with the recipient before dialing. The third is dialing during off-hours — San Marino uses local business hours and consumer phones are usually answered between 8 AM and 9 PM local time. The fourth and most expensive mistake is assuming your US carrier's WiFi calling feature makes the call cheap. It does not — see WiFi calling vs VoIP for international calls for why.

For scam-call awareness: +378 is the legitimate San Marino country code, and most unsolicited calls from +378 numbers are legitimate calls from San Marino-based businesses, hospitals, family members, or call centers serving US customers. Caller-ID spoofing exists, so if a call from a +378 number claims to be from a US government agency, your bank, or the IRS, hang up and call the agency back on its published number. Real authorities never demand payment over the phone.

When you are ready to place a call, the cheapest reliable route is to dial +378 from your browser using Kinvo — no app, no carrier add-on, and the per-minute rate is shown before you connect so there are no bill surprises. The browser approach also works from any laptop, tablet, or phone you happen to have access to, which matters when you're traveling, using a work device, or borrowing someone else's computer.