: While often per-minute, they sometimes offer a World Unlimited subscription for roughly $5.99/month that includes unlimited calls to many international destinations. 2. Major U.S. Carrier Add-ons
Finding reliable ways to make often depends on whether you are calling a landline or a mobile number, and if you prefer using a data-based app or a traditional phone service. 1. Top Unlimited Calling Plans (App-to-Phone)
: Their Global Calling Plus plan ($15/line/month) offers unlimited calls to landlines in 60+ countries and mobiles in 30+ countries. Unlimited Calls To Vietnam
: The International Calling add-on ($15/month) provides unlimited calling to 85+ countries, though Vietnam may be included as a discounted rate rather than unlimited. 3. Free App-to-App Alternatives
For 100% free unlimited calling, both parties must have the same app installed and a stable internet connection: Unlimited calling to Vietnam from USA using Ooma Telo : While often per-minute, they sometimes offer a
If you already have a plan with a major carrier, you can often add international calling for a flat fee, though "unlimited" usually applies to landlines while mobiles might incur a small per-minute rate.
: Provides unlimited minutes to landlines and mobiles starting from $10/month. Carrier Add-ons Finding reliable ways to make often
If you need to call actual phone numbers (not just other app users), these services offer dedicated monthly plans for Vietnam: