PhoneBlock

PhoneBlock is a free call-screening service built around a shared database of reported spam numbers. It is a strong fit for Android owners and people managing landlines who want open-source software and several deployment choices, while iPhone users face a less direct setup and business users should be cautious.

Overview

PhoneBlock’s protection grows from community reporting. Users can submit unwanted numbers in the app, on the website, or through a personal blacklist, and those reports become part of the shared blacklist. That approach can cover more nuisance callers than a private block list alone, but its usefulness depends on the quality and breadth of community contributions.

The project is licensed under GPL-3.0 and operated privately by Bernhard Haumacher. The website says it carries no advertising or third-party trackers. Its privacy policy says IP addresses from unregistered visitors are retained temporarily for error analysis and deleted after 14 days. Support is offered by email, including help when a legitimate number has been reported incorrectly.

Key features

Android protection

The Android app blocks known spam callers, records call history, accepts spam reports, and supports personal lists. Android 10 or later is required, excluding older phones. During incoming-call handling, it sends only the caller number’s SHA-1 hash and does not read contacts. That is a meaningful privacy advantage for users who do not want an anti-spam tool inspecting their address book.

Landlines and PBX systems

Landline households can connect PhoneBlock through a router dongle, a cloud answering machine working with Fritz!Box, or a CardDAV-synced blocklist phonebook. The answering-machine option stores the Fritz!Box IP address for registration and checks incoming numbers against the spam database, so it is not a purely local arrangement. Phone systems can download blocklists in several formats or query the service through an API; an integration page also links to a community 3CX project. These options make PhoneBlock more useful for mixed home setups and technically managed phone systems than an app confined to one handset.

iPhone route

The documented iPhone method synchronizes spam numbers into contacts through CardDAV. A native iPhone app is described as being in development, with beta registration offered. CardDAV can provide coverage, but it is less straightforward than a dedicated caller-protection app and may not suit readers who want an install-and-go experience.

Pricing

Plan	Price	Includes
PhoneBlock	free	Free to use; donations optional; caller ID and call screening on supported platforms

There is no free trial because the sole plan is free, and no paid tier or seat quota is stated. That removes subscription cost for personal use, but the terms advise against business use and put responsibility for resulting damage on the user. Organizations needing commercial assurances should therefore choose another service.

Platforms

PhoneBlock supports Android, iOS through CardDAV, web access, an API, and self-hosted use. Android requires version 10 or newer. Landline and PBX connections extend protection beyond mobile phones, while self-hosting and API access suit users who want control over integration.

Who it's for

Choose PhoneBlock if you want no-cost spam screening backed by community reports, use Android 10 or newer, or need a landline solution compatible with Fritz!Box, router hardware, CardDAV, or a PBX. It also suits technically confident users who value GPL-3.0 licensing, API access, or self-hosted options. It is a weaker choice for iPhone owners seeking a native app, people with older Android devices, and businesses that need terms designed for commercial deployment.

Pros and cons

Pros

• Community-maintained blacklist: reports from apps, the website, and personal lists feed a shared source of spam numbers.
• Broad connection options: Android, Fritz!Box answering machine, router dongle, CardDAV, PBX downloads, API, web, and self-hosting cover more than a single phone.
• Privacy-conscious Android handling: incoming calls use a SHA-1 number hash and do not require contact access.
• Free and open source: the 0.00 EUR plan has optional donations, and GPL-3.0 licensing permits inspection and reuse.

Cons

• iPhone compromise: CardDAV contact synchronization is the documented path until a native app arrives.
• Android cutoff: devices below Android 10 cannot use the app.
• Community dependence: coverage reflects the numbers users report, so unfamiliar spam may not appear immediately.
• Business caution: the terms discourage commercial use and assign responsibility for resulting damage to the user.
• Answering-machine data handling: Fritz!Box use requires storing the router IP for registration and checking caller numbers against the database.

Alternatives

For a wider comparison, see Spam Call Blocking Apps.

• Getcontact is a freemium Android, iOS, and web option; its Premium plan costs $2.99 a month and removes ads while adding tag-viewing information.
• YouMail fits users wanting cloud voicemail alongside blocking: its free tier includes 50 cloud messages, 100 voicemail-to-text transcriptions monthly, and unlimited known-spammer blocking.
• NumBuster offers a free mobile app plus paid feature and subscription tiers, making it an alternative when a tiered freemium model is acceptable.
• Hiya Spam Blocker provides free caller ID, basic blocking, and spam reporting, with Premium from $3.99 a month for readers who want a conventional mobile-app experience.
• RoboKiller includes global blacklist blocking, notifications, insights, reporting, and Spam Patrol in its free tier, with paid protection for those wanting more automation.
• Should I Answer? is another community-based choice with a free Android app and an iOS database-update option.
• Who Called is a free Android, iOS, and web app whose maker describes it as open source.
• Whoscall adds caller ID, call blocking, number/URL/screenshot checks, and scam reports in its free tier, with paid business-number features.

Verdict

PhoneBlock is the right pick for individuals who want free, community-powered spam blocking with unusually strong landline, PBX, API, and self-hosting flexibility. Its GPL-3.0 licence and restrained Android data handling strengthen the case. Look elsewhere if you need a native iPhone app today, support for pre-Android-10 devices, or business-friendly terms and guarantees.