Is the Ubigi eSIM for Japan Worth It? We Found A Better-Value Alternative

The Aussie start-up is also more affordable than Ubigi, giving you a fistful of leftover Yen to spend on anime and random vending machines. 

Let’s see how these two brands stack up in our ZenSim vs Ubigi eSIM Japan review.

WHAT IS AN ESIM?

The eSIM is a digital SIM card profile that lives on your phone's storage drive. Instead of inserting a plastic card with a microchip, you download and install the eSIM from a website or app. 

Once installed, your eSIM lies dormant until you arrive at your destination, when it automatically springs into action. That means you get a seamless connection upon touchdown and don’t have to stuff around buying a SIM card at the Tokyo Airport. 

Behind the scenes, the eSIM works like roaming by piggybacking off a local network. But unlike roaming, it won’t cost you an arm and a leg. 

WHY GET A PRE-PAID JAPAN ESIM?

The eSIM is a steal compared to roaming. Even the cheaper ‘Day Pass’ roaming plans are heaps more expensive on a trip of a week or more. Plus, with a pre-paid eSIM, you don’t have to worry about extortionate excess data charges. 

The other option is to get a local Japanese SIM card upon arrival. While this approach may work out cheaper, it’s a bit of a hassle, especially when you’re supposed to be on holiday. 

A local Japanese SIM requires finding a kiosk, queuing for service, handing over your passport, and opening that tiny SIM tray (hope you’ve got a safety pin). Next, you have to wait around while the attendant registers your IMEI and configures your APN. All this happens in a foreign language after a gruelling long-haul flight – yeah mate, nah.

The eSIM only takes minutes to set up and costs way less than roaming. 

ZENSIM VS. UBIGI: A JAPAN ESIM REVIEW

Founded in 2017, Ubigi is a French tech company that was acquired by NTT Group (Nippon Telegraph and Telephone), a major multinational headquartered in Tokyo. This corporation owns NTT Docomo, which operates Japan’s most extensive mobile infrastructure network. Ubigi offers eSIMs to 200+ destinations, including – of course – Japan. 

ZenSim is a small Australian-owned start-up also offering travel eSIMs for 201+ destinations. The lesser-known up-and-comer competes fiercely on price while offering fast, reliable connections through partnerships with some of the world’s best networks (including NTT Docomo). 

ORIGIN AND BRAND RECOGNITION

Ubigi is owned by a massive Japanese multinational. ZenSim, on the other hand, is a small Aussie start-up launched by a couple of easy-going blokes who left their corporate jobs in the telecommunications industry. 

Size doesn’t always equate to value, as big businesses often lack the human touch. Plus,  ZenSim appeals to Aussies who love supporting the underdog. 

• Winner: Case dependent

PRICE

The Ubigi eSIM for Japan for Australians costs about 10-15% more than ZenSim when paying in AUD. Ubigi is more competitive on USD payments, though still slightly more expensive. 

For a 30-day validity, the ZenSim 10GB costs A$3 ($2 USD) less, while its unlimited plan saves you A$7 (USD $5).

Ubigi doesn’t have a 20GB plan, and ZenSim doesn’t do 25GB, so we’re comparing two slightly different products here. If we break it down to dollars per gigabyte, ZenSim costs A$1.90/GB ($1.30/GB USD), while Ubigi is A$2.20/GB ($1.50/GB USD). 

• Winner: ZenSim (more so for AUD payments)

DISCOUNTS & SALES

ZenSim keeps things simple with a generous 10% repeat customer discount, which also applies to top-ups. Its ‘Squad Savings’ referral program gives you and your mates (or family/partner, etc.) A$5 off when signing up together. 

The UbiClub loyalty program lets customers earn UbiCoins for up to 8% cashback on eligible purchases. Its referral program gives you a 50% off coupon, and your friends 20% off on their first eSIM. 

• Winner: ZenSim for repeat purchases/top-ups, Ubigi for referrals. 

PARTNER NETWORK

Both Ubigi and ZenSim have multi-network eSIMs that automatically select the best available network. 

As you would expect, the NTT Group-owned Ubigi uses its own network, NTT Docomo, which has the best nationwide coverage in Japan, making it good for remote, rural and mountainous areas. Ubigi also partners with KDDI, known for great 5G coverage in densely populated cities. 

ZenSim has a small advantage as a tri-network eSIM. We partner with NTT Docomo for optimal provincial coverage, as well as Au (KDDI) and Rakuten Mobile for zippy 5G in the cities. ZenSim may perform better in certain situations, given that it has three networks to choose from (as opposed to Ubigi’s two).

• Winner: ZenSim

AVERAGE FEEDBACK SCORE

It would be unwise to rely entirely on marketing when selecting an eSIM. Online reviews from aggregator sites like ProductReview and Trustpilot paint a picture of real, on-the-ground performance. 

Ubigi has a 4.1/5.0 Trustpilot rating based on 41,000+ reviews, which, by eSIM industry standards, isn’t that flash. Most complaints revolve around activation issues or unexpected service interruptions. 

ZenSim proudly boasts a near-perfect 4.9/5.0 rating on ProductReview. Most punters praise the product for offering better value than other eSIMs. 

• Winner: ZenSim

UNLIMITED PLANS

Both ZenSim and Ubigi offer unlimited data plans in Japan and disclose their daily usage cap upfront. Ubigi’s is a little harder to find, as you have to click the ‘Fair Use Policy’ tab. 

ZenSim gives you 3GB per day, before throttling your connection to 1Mbps. Ubigi sets the usage cap per plan; in this case, it's 60GB per 30-day Japan eSIM (different limits apply to different plan lengths). 

Therefore, ZenSim gives you more unthrottled data in a 30-day plan, with up to 90GB per month compared to Ubigi’s 60GB/month. 

• Winner: ZenSim

TETHERING

Both brands include unlimited hotspotting, letting you tether your eSIM to another device without restrictions. You will, of course, be subject to standard eSIM data limits. 

• Winner: Tie

IN-APP TOP UPS

In-app top-ups mean you don’t have to mess around installing a new eSIM should you run out of data or extend your trip. 

Ubigi lets you top up in the app by adding a new plan with a suitable validity and data cap. You can also add data and days through the ZenSim mobile app, and top-ups attract a 10% discount. 

ZenSim has a cool additional feature that lets you add destinations to an existing eSIM. Should you fancy a sneaky side-trip to Taipei, for example, you can add Taiwan to your Japan eSIM. Destination top-ups are generally cheaper and easier than getting two separate plans. 

If you’re bouncing between numerous Asian nations, you might be better off with a ZenSim Asia eSIM instead, which covers 15 countries.  

• Winner: ZenSim

EASE OF INSTALLATION

Both eSIMs have three simple installation methods. We recommend trying them in the following order (if one doesn’t work, move on to the next). 

1. Direct: A one-click install through the app
2. QR code: Scan a QR code on a separate screen and follow the prompts
3. Manual: Follow instructions and copy-paste the eSIM code into your phone settings.

Even manual, the ‘hardest’ installation method, is simple and only takes a few minutes. 

The ZenSim help centre has step-by-step instructions for each method on most major smartphone types. See our eSIM compatibility checker beforehand.  

• Winner: Tie

CUSTOMER SUPPORT

Online support channels are ideal, as you don’t want to track down a regular telephone (nor pay inflated international calling rates) while on holiday. 

Ubigi handles customer support through a form on its website, and you receive a reply by email. Some disgruntled customers on Reddit have complained about responses taking up to 48 hours or being ignored altogether. Ubigi does have a WhatsApp number, but it's staffed entirely by an AI chatbot. 

ZenSim offers WhatsApp support with Australian agents (actual humans) across multiple time zones, working almost 24/7. If you don’t receive a response straight away, rest assured you will soon. 

• Winner: ZenSim

REFUNDS

According to the Ubigi terms & conditions, pre-departure refunds are only available if you have not scanned the QR code to install your eSIM. Refunds also aren’t available for carrier-locked phones.

Ubigi says used and/or activated eSIMs aren’t eligible for refunds unless there is a proven technical issue with Transatel. 

At ZenSim, we’re pretty easy-going. Our 100% money-back guarantee covers pre-departure refunds for any reason. Doesn’t matter whether you already installed the eSIM, have an incompatible/carrier-locked phone, or simply changed your travel plans. So long as you haven’t left home, we will give you a refund. 

If you’ve activated your eSIM, which happens automatically upon arrival in a destination country, the refund process gets a little trickier. We can’t make any promises, but please contact us to discuss the issue. 

• Winner: ZenSim

ZENSIM VS UBIGI ESIMS FOR JAPAN: THE VERDICT

Is Ubigi good in Japan? The eSIM isn’t bad, but there are lower-cost alternatives to consider.

ZenSim outperforms Ubigi on numerous metrics, including coverage, customer feedback, in-app top-ups, support, and refund flexibility. Despite the superior service, ZenSim also offers better prices, with AUD sales undercutting equivalent Ubigi Japan eSIMs by 5-15%. 

Grab your ZenSim Japan travel eSIM today and save.