How to check FTTH/Glasfaser availability and get a binding Netzbetreiber "Anschlusszusage" before you buy

1) Start with the Bundesnetzagentur Broadband Atlas (Breitbandatlas)

The Bundesnetzagentur operates the official Broadband Atlas (Gigabit‑Grundbuch). It is the authoritative public map of reported fixed‑network coverage including FTTH/FTTB and is the correct first check for any German address. The Atlas shows which operators report service at a given point and the technology category (for example FTTB/FTTH). The Atlas is a collection of operator data, not a sales offer; the entries are supplied by network operators and represent their reports on coverage. Always export or screenshot the map tile and the operator list with the timestamp shown on the page — that is the document you will use when you ask a seller or a network operator to confirm availability. (Source: Bundesnetzagentur Broadband Atlas and its public FAQ.)

Practical steps: open the Atlas, enter the precise street address and building number, note the displayed FTTH/FTTB status and the named providers, and save the page as PDF or PNG including the date shown by the portal. If the Atlas shows no FTTH at the address but shows FTTH nearby, list the providers it names; they are the parties to approach for a binding statement. (Sources: Gigabit‑Grundbuch / Breitbandatlas; Broadband FAQ.)

2) What the Atlas proves — and what it does not

The Atlas proves which operators report the capability to serve a location and gives a public record of reported coverage. It does not create a contractual right, a guaranteed installation deadline, or a customer service promise. Because the Atlas is an aggregate of operator submissions, you must treat it as evidence of reported network presence and then obtain operator confirmation in writing. The Bundesnetzagentur’s materials and press guidance explicitly state that the map is driven by operator data and is the central information source — not a contract. Use the Atlas extract as the factual starting point in any written request to a provider. (Source: Bundesnetzagentur Broadband pages and press release.)

If the seller cannot provide operator correspondence, treat that as a red flag: the presence shown on the Atlas without operator documentation is insufficient for legal certainty before purchase.

3) Exactly what to ask the seller to provide

Ask the seller for the following documents, dated and addressed to the property (building and unit number where relevant):

- The saved Breitbandatlas map extract (PDF/PNG) showing the address, providers and timestamp. - Any written availability or order confirmation from a named network operator mentioning this address (headings such as “Verfügbarkeitsbestätigung”, “Anschlusszusage”, “Technische Zusage” or a firm schriftliches Angebot to connect). The document should show the provider name, exact address, technology (FTTH/FTTB/FTTC), and any proposed activation or construction date. - If available: the operator’s cost estimate or verbindliches Angebot (price or cost estimate for bringing the fibre into the building), and any conditions (permission from the condominium association / Hausverwaltung, required internal cabling work).

Do not accept only a verbal statement from estate agents. Insist on a dated, signed PDF or letter from the operator or a formal ‘binding offer’ itemising works and a schedule. If the seller can produce only an operator web‑availability check screenshot, treat that as weaker evidence than an operator’s written offer.

4) How to obtain a binding "Anschlusszusage" from the operator

Use the provider names listed in the Atlas. Contact each provider’s business or construction order desk (use the contact shown in the Atlas or the operator’s customer‑service portal). In your written request include the Atlas extract and ask for a written, binding statement that must specify at minimum: the exact address, the technology (FTTH/FTTB), whether the operator will extend a fibre cable into the building, the Point of Interaction (POI) or basement entry point if known, any required permissions (HOA/WEG), the costs to the buyer and a realistic construction/activation date or window.

The Bundesnetzagentur’s materials make clear that the public map is operator supplied and that follow‑up queries to operators are the route to certainty. If an operator refuses to respond or only gives a non‑binding sales offer, you can ask for a formal written offer or contractor schedule — commercial offers are frequently used as binding evidence during conveyancing. If precise legal enforceability is required, instruct a German lawyer (Fachanwalt für IT/Telekommunikation or Immobilienrecht) before you sign. (Sources: Bundesnetzagentur Broadband Atlas, broadband FAQ.)

5) Practical cautions and next steps before signing

A signed sales contract does not force a network operator to build if no prior binding Zusage exists. Do not rely on promotional pages or national statistics alone: the Atlas shows coverage percentages nationally, but your contract position must be supported by an operator document tied to the property. For multi‑unit buildings, verify whether internal building cabling (from basement to flats) is already present — external fibre to the building means nothing if internal distribution requires separate works and consents. If you need absolute certainty, condition the purchase on receipt of a named operator’s written Anschlusszusage or a notarised warranty clause covering the connection work and timing. For enforceability and contract drafting use a German notary or lawyer. (Sources: Bundesnetzagentur pages; advice consistent with Atlas data origin.)

If you want us to prepare a short template request letter to send to a named operator or to draft a condition‑for‑contract clause you can present to a Notar, say which address and provider names you have and we will draft it.