congstar Review: Is the Telekom-Network Budget Brand Worth Choosing?

This guide is a research-based review, not a hands-on test. We have not been congstar customers and we did not order, activate or cancel a plan for this article. Everything below comes from congstar's own pages and from independent reviews, each linked, and we say plainly where we could not confirm something.

congstar is a German mobile brand owned by Deutsche Telekom. That single fact explains most of its appeal: it sells mobile tariffs over the Telekom network, but wrapped in simpler, cheaper, mostly online-only packages. If you have ever compared German mobile plans, you have seen it near the top of the list.

What congstar actually sells#

On the congstar website, the offer splits into two groups. The contract-style tariffs are the Allnet Flat range, which bundles calls, texts and data. At the time we looked they were listed as XS (15 GB), S (50 GB), M (125 GB) and L (200 GB). There is also a prepaid range, from a 1 GB option up to 50 GB, a flexible plan where you pick between 1 and 15 GB, and a yearly prepaid package with 240 GB a year.

Other things the site highlights:

• A 5G speed option you can add to a plan.

• eSIM support, described as fully digital and ready to use immediately.

• Monthly cancellable contract options.

• Partner or second cards with a customer discount.

• Roaming that now includes Switzerland in prepaid and eligible contract tariffs, from February 2025.

How this review was made#

We read the congstar homepage and tariff overview, then looked at independent reviews and rating platforms. We did not order a SIM, test speeds, or contact customer service. We also could not read exact monthly prices from the page we fetched, so this review does not quote any. That matters: German mobile prices move often, and introductory prices can differ from the price after the first months. Always read the tariff page on the day you order.

What the network is, and why it matters#

congstar uses what Germans call the D-Netz, the Telekom network. Review site smartweb.de describes it as Germany's best-quality network and says independent network tests support that. This is the strongest argument for congstar. Plenty of cheap tariffs exist, but few ride on the network that tops most coverage comparisons.

One caution: the same sources note occasional criticism about coverage in rural areas. A good national network is not the same as good signal in your village or inside your flat. Check Telekom's coverage map for your address before you commit.

What customers say#

Public ratings are strong. According to the summaries we read, congstar scores about 4.3 out of 5 on Trustpilot from roughly 9,000 reviews, 4.5 on Check24 and about 4.45 on Trusted Shops, from tens of thousands of verified reviews (handyhase.de summary, simdealz). Reviewers praise friendly service, network quality and a fair price for what you get. The advantages named most often are fast ordering and delivery, solid LTE and 5G reception, affordable data top-ups, EU roaming and a clear app.

Those figures were gathered from secondary sources when we looked, so check the live pages if the exact number matters to you.

Where it falls short, or where to be careful#

The honest answer here is "we could not find many serious complaints, and that is not proof there are none." Complaints that do come up:

• Rural coverage can be weaker than the headline network rating suggests.

• Price increases happen. German law gives customers a special right to cancel after one, according to the termination guides we read, but you have to act on it.

• Contract terms differ between tariffs. Some are monthly cancellable, others are not. Read the minimum term for the exact tariff you choose.

We also could not confirm what speed limit applies by default to each tariff, and the existence of a paid "5G speed" add-on suggests it is worth checking before you buy.

Price and value#

We cannot give a verdict on price without current figures, and we would rather say so than guess. What we can say is that congstar's positioning is clear: Telekom network quality at a lower price than Telekom itself, with fewer extras and mostly online service. If you value a shop to walk into, a competing network operator or Telekom directly may suit you better.

Who should choose congstar, and who should look elsewhere#

Choose congstar if you live in Germany, want strong network quality, are comfortable managing your plan in an app, and like having both contract and prepaid options.

Look elsewhere if you rely on in-person support, live somewhere where Telekom reception is known to be poor, or want the absolute cheapest data per euro and are happy with a weaker network.

The verdict#

congstar looks like a solid, widely praised budget brand that rides on a premium network. The weakness of this review is also its honesty: we have not been customers, we have not tested the service, and we could not read live prices. Use it to decide whether congstar belongs on your shortlist, then read the tariff and terms on the day you order. The discount codes below may save you money, but they do not change any of the above.

Disclosure: Topicnix earns a commission if you buy through some links on this site, at no cost to you. This guide was written from published information and independent reviews, not from a purchase, and the commission has no effect on what we write.