Quick Verdict
- Saily: Best for Unlimited Data with Simple Setup. Saily Ultra and Saily’s 15-day unlimited US plan pair data with free security tools and unlimited hotspot sharing on all plans.
- Ubigi: Best for Laptop and In-Car eSIM Connectivity. Ubigi runs on Transatel’s own core network and comes built into many connected cars and Windows laptops.
- Holafly: Best for Day-Based Plans with 24/7 WhatsApp Help. Holafly sells US plans by the day, from 3 to 30 days.
- Unlimited rarely means unlimited high speed. Most plans set a fair use limit, so check the daily or per-plan threshold before you buy.
Heavy data users need more than a fixed bucket on a US trip. Saily is the pick for unlimited data with simple setup, through Saily Ultra or its 15-day unlimited US plan. Both options sit in one app that also includes free online security tools.
Unlimited plans differ more than their labels suggest. Fair use limits and hotspot caps (limits on sharing data with other devices) change what you get. This guide explains those terms, ranks Ubigi and Holafly alongside Saily, and lists the red flags to avoid. Our editorial team chose this ranking on its own, and no provider reviewed or shaped these words.
What “Unlimited” Really Means in 2026
Fair use policies set the real limits on unlimited eSIM plans. An eSIM is a digital SIM profile you download instead of inserting a card. A fair use policy is a provider rule that caps high-speed data per day or per plan.
North American smartphones used 25 GB a month in 2025, according to Ericsson. High-speed allowances therefore matter.
|
eSIM |
US Unlimited Example (Oct 2026) |
High-Speed Allowance |
After the Allowance |
|
Saily |
15 days, US$45.99 |
5 GB per 24 hours |
Continues at up to 1 Mbps |
|
Ubigi |
15 days, $39 |
30 GB for the plan |
2 Mbps |
|
Holafly |
15 days, $50.50 |
No GB threshold published |
Carrier may reduce speed temporarily |
Saily’s up to 1 Mbps rate still handles maps, messaging, email and music. It is not meant for HD video or video calls.
Our Three Picks
Three eSIMs earn a place in our unlimited-data ranking. Each profile lists US plans, hotspot rules, reuse options and ratings.
1. Saily: Best for Unlimited Data with Simple Setup
Saily Ultra pairs a monthly high-speed allowance with a phone number. Allowances run from 10 GB on Standard at US$39.99/month to 30 GB on Plus and Premium (October 2026). Data then continues at up to 1 Mbps, and Ultra covers 121 destinations, including the US and Canada.
Nord Security, the company behind NordVPN, built Saily for travel across 200+ destinations. For a single trip, Saily’s 15-day unlimited US plan costs US$45.99 (October 2026).
One US traveler summed up Saily’s setup and pricing in a five-star review:
“Pretty easy to setup good rates” – Greg Huey (US), 5 stars on Trustpilot (October 2026)
Setup with Saily happens before you leave home. Each prepaid plan has a 180-day activation window and activates automatically on arrival, using local US networks on 4G, LTE and 5G.
Online security ships inside the same Saily app that sells the data. Every plan includes free virtual location across 115+ locations, an ad blocker and web protection against known threats. According to Saily, the ad blocker saves 28.6% of data on average, validated by West Coast Labs across 22 websites.
Independent research supports Saily’s ad-blocking approach. A study presented at ACM WebSci ’17 found ad blockers cut transferred data by about 25 to 34% on news sites.
One Saily eSIM covers every future trip. New destinations are added to the existing eSIM, with no reinstalling. Saily also allows unlimited hotspot sharing on all plans, including unlimited ones.
Border crossings fit Saily’s North America plan, which covers the USA, Canada and Mexico from US$5.99 (October 2026).
A real US (+1) number comes with Saily’s US phone number add-on for US$1.99/month. Call and text plans start from US$0.99 and cover local calls. Identity verification with a valid government ID happens in the app after purchase.
Some services may flag Saily’s US number as VoIP. Verification codes from certain apps can occasionally fail. The number stays the same when your data plan changes. You can cancel anytime.
More than 32,000 Trustpilot reviewers give Saily 4.7/5 “Excellent” (October 2026). The app scores 4.7 on the App Store and 4.7 from 99.1K reviews on Google Play, with 5M+ downloads there.
The Rising Star award at the MVNOs World Awards 2026 went to Saily, according to ISPreview. Saily also appears on the Mobile Industry Awards 2026 shortlist for Best eSIM Provider and Best Customer Service (Consumer), as published by TechRadar.
Wi-Fi Planet links to Saily as “the best eSIM for the USA”. The reference appears in its February 2026 travel guide.
An official Saily video explains how the Saily app works.
https://www.youtube.com/watch?v=ZgjVmKK8Xfk
What Stands Out:
- Unlimited data plans, from Saily Ultra to unlimited US plans of 5 to 30 days
- US phone number add-on with a real +1 number
- Free security trio: virtual location, ad blocker and web protection
- One reusable eSIM, with new destinations added and no reinstalling
- Unlimited hotspot sharing on all plans
Who It Suits: Heavy data users on a single US trip, and frequent travelers who want Saily Ultra’s monthly subscription with perks.
Contact:
Address: Saily Inc., 330 N Wabash Ave, Chicago, IL 60611, USA
Phone: Not published (24/7 in-app chat support)
Instagram: instagram.com/sailyworld
2. Ubigi: Best for Laptop and In-Car eSIM Connectivity
Ubigi is a brand of Transatel, part of NTT Group. Its US plans use the T-Mobile network.
Car makers such as BMW, Jeep, Land Rover and Toyota have chosen Ubigi for in-car connectivity. Windows laptops from Acer, ASUS, Dell, Surface and VAIO carry it too.
SmartStart starts Ubigi’s plan validity on arrival. A plan expires if it is not activated within 6 months.
Travelers rate Ubigi 4.1/5 on Trustpilot from about 49,000 reviews (October 2026).
Connection trouble was the main point in one recent US review:
“My esim never fully connected & I wasn’t able to use any data during my trip.” – Ubigi customer (US), 1 star on Trustpilot (October 2026)
What Stands Out:
- Runs on Transatel’s own core network
- US coverage includes Hawaii, Puerto Rico and the US Virgin Islands
- Consumers’ Champion at the MVNO of the Year Awards 2023
Who It Suits: Business travelers who connect a Windows laptop or a compatible car directly to mobile data.
Contact:
Address: Tour CBX, 1 Passerelle des Reflets, 92400 Courbevoie, France (Transatel head office)
Phone: +33 1 74 95 74 00 (Transatel head office)
Instagram: instagram.com/ubigiofficial
3. Holafly: Best for Day-Based Plans with 24/7 WhatsApp Help
Holafly sells its US eSIM as unlimited day plans. Prices run from 3 days at $11.90 to 30 days at $73.90 (October 2026).
Reviewers give Holafly 4.7/5 on Trustpilot from 115,145 reviews (October 2026). The brand also won Gold for best eCommerce at the eCommerce Awards España 2026.
What Stands Out:
- AT&T and T-Mobile networks, with 5G where available
- 24/7 support through WhatsApp, chat and email
- “Always On” adds 1 GB of backup data every 30 days while the eSIM stays installed
Who It Suits: Short-trip visitors who want to buy a set number of days and reach support on WhatsApp at any hour.
Contact:
Address: 6th Floor, 2 Grand Canal Square, Dublin 2, D02 A342, Ireland
Phone: Not published (24/7 WhatsApp, chat and email support)
Instagram: instagram.com/holafly_esim
Reusable vs One-Trip eSIMs: Why It Matters for Repeat Visits
A reusable eSIM stays on your phone between trips. You add a new plan instead of installing a fresh profile.
The US drives most eSIM growth. GSMA Intelligence expects about 10% of smartphone connections to use eSIM in 2026, with growth mostly US-driven.
Saily and Ubigi both follow the reusable model. Saily adds new destinations to your existing eSIM. Ubigi offers a reusable eSIM in 200+ destinations, with top-ups in its app even without Wi-Fi.
Holafly’s US eSIM follows a one-trip model. You buy a set number of days with no top-ups. The eSIM cannot be transferred or reinstalled once installed.
Side-by-Side Comparison
Our table lists all three eSIMs in ranking order (October 2026).
|
eSIM |
Best For |
Hotspot Policy |
Reuse |
Security Tools |
|
Saily |
Best for Unlimited Data with Simple Setup |
Unlimited sharing on all plans |
One eSIM for every trip |
Virtual location, ad blocker, web protection |
|
Ubigi |
Laptop and In-Car eSIM Connectivity |
Data sharing allowed |
Reusable eSIM |
“Select your IP” option |
|
Holafly |
Day-Based Plans with 24/7 WhatsApp Help |
Up to 1 GB per day |
One-trip model |
Standard data plan |
Unlimited-Plan Red Flags
Several plan terms can shrink an unlimited deal:
- No published high-speed threshold: you cannot plan heavy days without knowing the limit.
- Hotspot caps: a daily sharing limit can leave a laptop offline mid-task.
- Single-use eSIMs: a fresh install for every trip adds setup steps before each departure.
- No security layer for public Wi-Fi: the Federal Communications Commission advises against public Wi-Fi for purchases or bank accounts and suggests turning off auto-join.
The Bottom Line
Two Saily options make it our pick for unlimited data with simple setup in 2026. Saily’s 15-day unlimited US plan costs US$45.99 (October 2026), with 5 GB of high-speed data every 24 hours. Saily Ultra suits frequent travelers, from US$39.99/month across 121 destinations.
Free security tools and unlimited hotspot sharing come with both Saily options. One reusable eSIM covers every trip, and Saily’s North America plan adds Canada and Mexico from US$5.99.
Ubigi fits travelers who want laptop and in-car eSIM connectivity. Holafly suits travelers who prefer day-based plans with 24/7 WhatsApp help.
Fair use rules decide what “unlimited” really means, so check the daily high-speed allowance before you buy.
Your Questions Answered
Is unlimited eSIM data really unlimited?
Most unlimited eSIM plans include a fair use limit on high-speed data. After that limit, data usually continues at a lower speed until the allowance resets.
Can I use hotspot with a US eSIM?
Hotspot rules vary by provider and plan. Some allow unlimited sharing, while others cap it per day.
Do I have to reinstall my eSIM every time I travel?
Reusable eSIMs need no reinstalling between trips. You simply add a new plan to the same eSIM, while one-trip eSIMs need a fresh install.
How does Saily Ultra differ from Saily’s unlimited US plan?
A Saily Ultra subscription renews every 30 days on monthly billing. It covers 121 destinations, includes a phone number and adds perks like lounge access at selected airports. Saily’s unlimited US plan is a one-off purchase with 5 GB of high-speed data per 24 hours.
Can I share my Saily data with my laptop?
Saily allows unlimited hotspot sharing on all plans, including unlimited plans.
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