Oister Mobile Denmark: Cheap Plans and Data 2026

Oister is one of the most prominent budget mobile providers in Denmark, offering low-cost data plans and flexible subscriptions for residents. For many expats and international residents, Oister represents a cost-effective entry point into the Danish telecommunications market. However, accessing these standard subscriptions requires specific documentation that new arrivals often lack immediately upon landing.

Understanding how Oister operates within the broader context of mobile plans in Denmark is essential for choosing the right service. The Danish mobile market is highly competitive, resulting in generally low prices and high data allowances compared to many other European countries. Most providers, including Oister, operate as digital-first companies with limited physical presence.

The Main Network Providers

To understand the quality and coverage of a provider like Oister, it is necessary to understand the infrastructure behind it. Denmark has three main network operators that own the physical cell towers and infrastructure. These are TDC NET, the Telia/Telenor joint network (TT-Network), and the 3 network (Hi3G Denmark).

Every other mobile brand in the country is a Mobile Virtual Network Operator (MVNO). These smaller companies rent capacity from one of the three main infrastructure owners. This system allows for significant price competition while maintaining high-quality coverage across the country.

Oister and the 3 Network

Oister is owned by Hi3G Denmark, the company behind 3 mobile Denmark. Consequently, Oister customers utilize the 3 network for all calls and data. This relationship means that Oister users experience the exact same coverage and speed as premium customers on the main 3 brand.

The 3 network is historically strong in major urban areas such as Copenhagen, Aarhus, Odense, and Aalborg. It offers high-speed data connections and extensive 5G availability in cities. In very rural areas or remote parts of Jutland, coverage may differ slightly from the TDC network, which is often cited as having the widest rural reach.

Requirements for Subscribing to Oister

Getting a mobile contract in Denmark is different from buying a SIM card in many other countries. The system is highly digitized and integrated with the national civil registry. Oister, like almost all postpaid subscription providers in Denmark, enforces strict sign-up requirements.

The CPR Number Requirement

To sign up for a subscription with Oister, you must possess a Danish CPR number (Civil Registration Number). This is a ten-digit personal identification number issued to residents. You cannot bypass this requirement for a standard monthly plan. The provider uses the CPR number to validate your identity and creditworthiness.

MitID and Digital Verification

In addition to the CPR number, you generally need MitID to complete the sign-up process online. MitID is the Danish digital signature and login system used for banking, government taxes, and private services. When you purchase a subscription on the Oister website, you will be asked to sign the agreement digitally using MitID.

Danish Address and Bank Account

The system requires a registered Danish address. Your SIM card is typically mailed to this address to prevent fraud. Furthermore, payment for monthly subscriptions usually requires a Danish payment card (Dankort, Visa/Dankort) or a registration with Betalingsservice (direct debit). Foreign credit cards are frequently rejected by automated recurring payment systems in Denmark.

Options for Expats Without a CPR Number

New arrivals often face a “Catch-22” scenario. You need a phone number to register for various services, but you need a CPR number to get a phone contract. If you have just arrived and do not yet have your CPR number or MitID, you cannot sign up for Oister immediately.

In this transitional phase, you must rely on prepaid options. Prepaid services do not require a CPR number or a contract. You can purchase these starter kits at convenience stores (like 7-Eleven), supermarkets, or kiosks at the airport.

Prepaid Alternatives

The most common prepaid providers for non-residents are Lebara Denmark and Lyca Mobile. These operators run on the Telenor/Telia network. They allow you to register a SIM card using just a passport or foreign ID. Once you receive your CPR number and get settled, you can easily port (transfer) this number to a cheaper or more feature-rich plan with Oister.

Mobile Plans and Pricing Overview

Danish mobile plans are generally structured as “packages.” You pay a fixed monthly fee for a specific amount of data and voice minutes. Unlimited texting is standard across almost all plans. The following table illustrates the typical tiers of service you will find in Denmark, comparing prepaid options with standard subscriptions like those from Oister.

Plan Type	Target Audience	Data Allowance (DK)	EU Roaming Data	CPR Required?	Approx. Price (DKK/month)
Prepaid / Pay-as-you-go	Tourists, New Arrivals	10 GB – 100 GB	2 GB – 5 GB	No	99 – 149 DKK
Budget Subscription (e.g., Oister)	Residents, Students	20 GB – 200 GB	10 GB – 20 GB	Yes	59 – 109 DKK
Unlimited Data Plan	Heavy Users, Commuters	Unlimited	25 GB – 35 GB	Yes	159 – 199 DKK
Premium / Family Plans	Families, Business	Unlimited + Streaming	30 GB+ (or World)	Yes	229 – 299 DKK

The value proposition in Denmark is high. For approximately 100 DKK (roughly 13-14 EUR), you can often secure a plan with over 50 GB of data. Oister frequently runs promotions where they double the data allowance or offer the first month for free. There are rarely activation fees for online orders, though shipping fees for physical SIM cards may apply.

Most subscriptions, including Oister, operate on a “no binding” basis. This means there is no 12-month or 24-month lock-in contract. You can typically cancel your subscription with 30 days’ notice. This flexibility is highly advantageous for expats who may not know how long they will remain in the country.

EU Roaming and Data Limits

Denmark is a member of the European Union, which means “Roam Like at Home” rules apply. However, this does not mean you can use your full domestic data allowance while traveling in other EU countries. Providers apply a “Fair Use Policy” cap to roaming data.

When you look at an Oister plan, you will see two data figures. The first is the total data available for use within Denmark (e.g., 100 GB). The second is the portion of that data available for use in the EU/EEA (e.g., 10 GB). If you exceed the EU limit while traveling, you will be charged a surcharge per gigabyte, regulated by EU law.

Oister vs. 3LikeHome

It is important to distinguish between Oister and its parent company, 3. The premium brand “3” offers a service called “3LikeHome,” which allows users to use their data in many countries outside the EU (such as the USA, UK, and Thailand) without extra cost. Oister generally does not include this global roaming feature. Oister plans are typically restricted to EU/EEA roaming. If you travel frequently outside of Europe, the budget savings of Oister might be offset by roaming costs.

Physical SIM vs. eSIM Technology

The telecommunications industry is shifting away from plastic SIM cards toward digital embedded SIMs (eSIMs). eSIM Denmark adoption is growing, and most major carriers support this technology.

How eSIM Works with Oister

Oister supports eSIM technology. If you have a compatible phone (such as a newer iPhone, Samsung Galaxy, or Google Pixel), you can choose an eSIM profile instead of a physical card. This is delivered via a QR code or an app. This eliminates the need to wait for a physical letter in the mail.

However, the requirement for a CPR number and MitID remains. You cannot simply download an Oister eSIM from abroad to have a working Danish number upon arrival. The digital identity check must still be performed before the eSIM profile is released to you.

Travel eSIMs for Immediate Connectivity

For immediate connectivity upon landing, many travelers use international travel eSIM providers (like Airalo or Holafly). These are data-only plans. They do not provide a Danish phone number (+45). They are useful for using maps and messaging apps during your first days in Denmark, but they do not replace a proper Danish subscription for long-term residency needs.

5G Availability and Speeds

Denmark has rapidly rolled out 5G infrastructure. Oister includes 5G access in most of its mid-tier and upper-tier plans. Since they utilize the 3 network, Oister customers benefit from the extensive 5G rollout that 3 has conducted in major metropolitan areas.

The 5G experience offers lower latency and higher throughput. For standard mobile usage—social media, web browsing, and music streaming—4G LTE remains perfectly adequate and covers nearly 100% of the population. You generally do not need to pay a significant premium specifically for 5G unless you are tethering your connection to a laptop for work or gaming.

Mobile Broadband and Home Internet

Many expats in Denmark choose to forego a traditional fiber or coax cable internet connection in favor of mobile broadband Denmark solutions. Oister offers data-only SIM cards designed for use in 4G or 5G routers.

These plans usually offer significantly higher data caps (e.g., 1000 GB or “Unlimited”) compared to phone plans. This can be a flexible solution for renters who cannot drill holes for cables or who move apartments frequently. You simply plug the router into a power outlet, and you have Wi-Fi. Note that the router itself is often a separate purchase or an additional monthly rental fee.

Customer Service and Self-Service

As a budget provider, Oister focuses heavily on self-service. They keep costs low by minimizing telephone support. Customers are expected to manage their accounts through the “Mit Oister” (My Oister) online portal or mobile app.

Language Support

The Oister website and self-service app are primarily in Danish. While many Danes speak excellent English, the interface for budget companies is rarely translated. Expats will often need to use browser translation tools (like Google Translate in Chrome) to navigate the sign-up forms and account settings.

If you call their customer support line, the agents will almost certainly speak English. However, the automated voice menus (IVR) leading up to the agent will likely be in Danish. It is helpful to learn the Danish words for “press one” (tast et) and “support” (kundeservice).

Switching Providers in Denmark

The Danish telecom market is designed to make switching providers extremely easy. If you start with a prepaid card or a different provider and wish to switch to Oister, you do not need to cancel your old subscription manually. You simply sign up with Oister and request a “nummerflytning” (number transfer).

You will provide your current phone number and the name of your current operator during the Oister checkout process. Oister will then contact your old provider, cancel your old plan, and move your number to their network. This process usually takes 30 days due to standard notice periods, but it is automated. You will receive a date when the switch happens; on that day, you swap the SIM cards.

Managing Data Top-Ups and Changes

Flexibility is a key feature of the Danish mobile market. If you find that you are running out of data consistently, you can usually upgrade your plan instantly via the provider’s app. Downgrading is also possible, though it often takes effect from the following month.

With Oister, additional data can be purchased as “add-ons” if you hit your limit before the month ends. However, it is usually more economical to upgrade to the next plan tier rather than buying small data packages repeatedly. The price difference between a 20 GB plan and a 100 GB plan is often as low as 20-30 DKK.

Coverage in Remote Areas

While Denmark is flat and generally has excellent coverage, there are differences in rural performance. The 3 network (Oister) utilizes high-frequency bands that are excellent for capacity in cities but travel shorter distances. To compensate, 3 has roaming agreements for domestic roaming in certain dead zones, but your phone will primarily seek the 3 towers.

If you plan to live in a very remote farmhouse in West Jutland or on a smaller island, it is advisable to check coverage maps specifically for the 3 network before committing. In these specific rural scenarios, providers on the TDC network might offer stronger signal penetration through dense forests or rolling terrain.