Privacy Policy

Last updated: October 12, 2026

This Privacy Policy explains how DuckingBlock (“DuckingBlock”, “we”, “us”) collects, uses, shares and protects personal information when you use the DuckingBlock iPhone app and the duckingblock.app website (together, the “Service”). DuckingBlock is an iPhone spam-call and spam-text blocker with an optional caller-ID / number-lookup feature.

DuckingBlock is operated by Ducking LLC, which is the data controller for your personal information. We built the Service to need as little of your data as possible: we do not sell your personal information, we do not share it for cross-context behavioral advertising, and the app contains no advertising SDKs or third-party ad trackers.

Because privacy laws differ by where you live, this policy has region-specific sections. Read the global section that applies to everyone, plus the section for your region: the EU/EEA, UK & Switzerland (GDPR) section or the United States & California (CCPA/CPRA) section.

How to request deletion of your data

You can delete the data DuckingBlock holds about you at any time, by any of these methods:

In the app — open Protection and, under the caller-ID / “Share contacts” section, tap Stop sharing to delete every contact you have shared. On iPhone, if you signed in, use Settings → Delete account to erase your account identifiers, session, shared contacts and attribution links.
Remove a specific phone number from our caller-ID or spam data — including your own number — using our removal / appeal form.
By email — write to [email protected] and we will delete your data and confirm by email.

Full detail is in section 7 (Your choices & account deletion) and section 8 (Removing a number). Records we are legally required to keep, and blocklist evidence that does not identify you, may be retained in anonymized or aggregated form.

1. Information we collect and why (all users)

We collect only what the Service needs to block spam and, when you ask for it, tell you who is calling. The categories below apply to everyone; your regional section adds the legal detail.

Account identifiers (Sign in with Apple). Signing in is optional and powers number lookup, your personal block list and spam-report attribution. When you sign in, Apple gives us a stable, app-specific Apple user ID, and — only if you choose to share it on first sign-in — your name and an email address (which may be Apple’s private-relay address). We also issue an opaque session token so you stay signed in. We use this to recognize your account across devices and reinstalls, to apply your subscription entitlement and lookup quota, and to contact you if needed.
Phone numbers you look up. When you use Number Lookup, the number you query is sent to our servers (and, if needed, to our telecom provider) to return a caller name, line type, carrier and region. See section 3.
Contacts you choose to share. Only if you opt in, name↔number pairs from your address book. See section 2 — this is the most privacy-sensitive feature and is entirely optional.
Spam reports you submit. If you report a number as spam/scam/robocall, we receive that number and the category. If you are signed in, the report may be attributed to your account (for example to recognize top contributors); you can also report anonymously. We do not receive the rest of your call or message activity.
Appeal / removal requests. If you use our removal form, we collect the number, your email, whether you own or are authorized for the number, whether it is a business, an optional business name, and your reason, so we can review and respond.
Subscription status. Premium billing is handled by Apple. The app sends us the App Store signed transaction so our server can verify your entitlement with Apple and unlock Premium. We store a premium flag and expiry date — not your payment-card details, which we never see.
Diagnostics. If you opt in, aggregate, non-identifying crash and performance data to keep the app stable.

What we do not collect: your call history or the numbers that call you (blocking happens on your device — see section 4), your message contents, your microphone or call audio, your precise location, or advertising identifiers.

2. Contacts sharing & other people’s data

Contacts sharing is strictly opt-in. DuckingBlock works fully without it. If — and only if — you choose to enable it, the app uploads name↔number pairs from your address book so that our caller-ID feature can show a likely name for an unknown caller (a number’s most-commonly-shared name becomes the crowd-sourced caller ID).

Please read this carefully: your address book contains personal information about other people. By enabling contacts sharing, you confirm that you are allowed to share those contacts with us, and you act as the source of that data. We use shared contacts only to improve caller identification within the Service. We do not publish your address book, show whose contacts a name came from, sell this data, or use it for advertising.

If a contact’s name is itself a spam label (for example “Scam Likely” or “Do Not Answer”), we do not store that text as a caller-ID name. Instead we record the number as a single anonymous, de-duplicated community spam signal that needs corroboration from multiple independent sources before it affects anyone’s blocking — one person’s label can never block a number for everyone.

You can withdraw contacts sharing at any time and delete everything you have shared from within the app (this calls our delete-contacts function and removes your shared-contact records). A person whose number appears in our caller-ID or spam data — whether or not they use DuckingBlock — can ask us to remove it; see section 8.

3. Number Lookup & caller ID

Number Lookup lets a signed-in user check an unknown number. The free, unlimited result (spam verdict, carrier, region and line type) is computed from our own data and an offline numbering database. A caller name may additionally be resolved through a cost-limited cascade: our own data → opt-in shared contacts → a short-lived operational cache → and, only if still unresolved and you have lookup quota remaining, a single CNAM (caller-name) lookup through our telecom provider, Telnyx.

When a CNAM lookup is needed, the queried number is sent to Telnyx, which returns the registered display name. We hold CNAM results only in a private, access-controlled operational cache with a time limit, so we don’t repeatedly query the same number. This cache is not a public directory, is never exposed as a standalone endpoint, and is never resold. Name lookups are quota-limited per account per month (a small free allowance, a larger Premium allowance).

4. The spam blocklist & how blocking works

DuckingBlock registers as an iOS Call Directory and message-filter extension. We deliver a list of known-spam numbers to your iPhone, and iOS matches incoming calls and texts against that list locally, on your device. The result of a block is not reported back to us; we do not learn who called you.

Our spam list is compiled from public-domain regulator complaint data (for example US FTC and FCC consumer-complaint datasets), other reputable sources, and corroborated community reports. A number is listed based on a weighted evidence threshold, never on a single unverified report. See our listing criteria for how numbers are added and removed.

We do not sell your personal information and we do not share it for advertising. We disclose data only to:

Service providers (processors) who help us run the Service under contract, including our telecom caller-name provider (Telnyx), our hosting/infrastructure provider, and Cloudflare (which serves the website and screens the appeal form for abuse). They may process data only on our instructions.
Apple, which operates Sign in with Apple and handles all subscription billing.
Legal / safety: where we must comply with law, enforce our Terms, or protect the rights and safety of users and the public.
Business transfer: if Ducking LLC is involved in a merger, acquisition or asset sale, data may transfer as part of that transaction, subject to this policy.

6. Data retention

We keep personal information only as long as needed for the purpose it was collected, then delete or anonymize it:

Account data — while your account exists; deleted when you delete your account (see section 7).
Shared contacts — until you delete them or your account.
CNAM caller-name cache — kept only for a limited operational window and then refreshed or expired.
Spam reports, appeal/removal requests and blocklist evidence — retained as needed for the integrity of the blocklist and to handle disputes and abuse.

Specific retention periods are set out in our internal data-retention schedule and may be adjusted to meet legal and operational requirements.

7. Your choices & account deletion

You control the sensitive features: contacts sharing, number lookup and spam reporting are all optional, and you can turn contacts sharing off and delete your shared data at any time in the app.

Account deletion. You can delete your DuckingBlock account at any time. Deleting your account removes your account identifiers, session tokens, shared contacts and attribution links. You can request deletion from within the app or by emailing [email protected] from (or referencing) your account. Blocklist evidence that does not identify you, and records we must keep for legal reasons, may be retained in anonymized or aggregated form.

Depending on where you live, you also have the formal data-subject or consumer rights described in section 9 (GDPR) or section 10 (CCPA/CPRA). To exercise any right, email [email protected].

8. Removing a number from our database

If a phone number has been listed as spam or appears in our caller-ID data and you believe that is wrong — or you own the number and want it removed — you can ask us to review and unlist it using our removal / appeal form. This is our standard mechanism for the “remove my number” request, including requests to erase personal data under the GDPR. We review every request, respond by email, and clear numbers that do not belong on the list. You can also write to [email protected].

9. EU/EEA, UK & Switzerland (GDPR)

If you are in the European Economic Area, the United Kingdom or Switzerland, this section applies to you and prevails over any conflicting statement elsewhere in this policy.

Data controller. Ducking LLC is the controller of your personal data. Contact us at [email protected] for any privacy matter, including to reach our data protection point of contact.

Legal bases. We process personal data on these bases:

Performance of a contract — to provide the app, your account, subscription entitlements and number lookups you request.
Consent — for optional contacts sharing and any optional diagnostics. You may withdraw consent at any time, without affecting prior processing.
Legitimate interests — to maintain and improve the spam blocklist, keep the Service secure, prevent abuse and fraud, and defend our rights. Where we rely on legitimate interests we have balanced them against your rights, and you may object (below).
Legal obligation — to comply with laws that apply to us.

Your rights. You have the right to access, rectify, erase (“right to be forgotten”), restrict and object to processing, to data portability, and to withdraw consent. To erase a phone number from our blocklist or caller-ID data, use the removal form. To exercise other rights, email [email protected]; we will respond within the time the GDPR requires. You also have the right to lodge a complaint with your local supervisory authority.

Third-party data via contacts. When a user shares their address book, that data includes people who are not DuckingBlock users and who did not give us their data directly. We rely on the sharing user’s representation that they may share it, and on our legitimate interest in providing caller identification and spam protection, balanced with strong safeguards: the data is used only within the Service, is never published or sold, a single user’s label cannot block a number, and any person can have their number removed on request. See the transfers section for how we handle data leaving the EEA.

10. United States & California (CCPA/CPRA)

This section provides the disclosures required by the California Consumer Privacy Act, as amended by the CPRA, and offers comparable rights to residents of other US states with consumer-privacy laws.

We do not sell your personal information, and we do not “share” it for cross-context behavioral advertising, as those terms are defined under California law. We have not done so in the preceding 12 months. We do not knowingly sell or share the personal information of minors.

Categories we collect. Identifiers (Apple user ID, optional email/name, session token, phone numbers you look up or report); commercial information (subscription status); internet/app activity (optional diagnostics); and contact information from your address book if you opt into contacts sharing. We collect these for the business purposes described in section 1 and do not use sensitive personal information to infer characteristics.

Your rights. California residents (and residents of other states with similar laws) may request to know and access the personal information we hold, request correction, request deletion, and opt out of sale/sharing (we do not sell or share, so there is nothing to opt out of). We will not discriminate against you for exercising these rights. To make a request, email [email protected]; to remove a phone number from our database, use the removal form. You may use an authorized agent; we may need to verify your identity before acting.

11. Children

DuckingBlock is not directed to children and is not intended for anyone under 13 (or the minimum age of digital consent in your country). We do not knowingly collect personal information from children. If you believe a child has provided us data, contact [email protected] and we will delete it.

12. International data transfers

DuckingBlock is operated from the United States, and our service providers (including Telnyx) are located in the United States. If you use the Service from outside the US, your personal data will be transferred to and processed in the US and other countries whose data-protection laws may differ from yours. Where we transfer personal data out of the EEA, the UK or Switzerland, we rely on appropriate safeguards such as the European Commission’s Standard Contractual Clauses (and the UK/Swiss addenda). Contact us for more information about these safeguards.

13. Security

We protect data with access controls, encryption in transit, server-side verification of Sign in with Apple and subscription receipts, and a least-data design. No method of transmission or storage is perfectly secure, but we work to protect your information and to limit what we hold in the first place.

14. Changes & contact

We may update this policy as the Service or the law changes. We will revise the “Last updated” date above and, for material changes, provide a more prominent notice. Your continued use of the Service after an update means you accept the revised policy.

Questions, requests, or privacy concerns? Email [email protected]. Our Terms of Service are available here.

Data controller: Ducking LLC · Contact: [email protected]

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