Supplement to the Block9 LLC Privacy Policy

Effective Date: April 30, 2026

Last Updated: April 30, 2026

Scope. This Addendum supplements the Block9 LLC Privacy Policy and addresses only the data considerations that are specific to blockchain technologies and peer-to-peer cryptocurrency payments. For Block9's general data practices, individual rights (including under the CCPA), retention, and contact information, please refer to the main Privacy Policy and the California Privacy Notice at www.block9.app. This Addendum applies solely to www.block9.app and the consulting, education, workshop, and merchandise offerings of Block9 LLC. Other Block9-affiliated products operated under separate domains are governed by their own privacy notices.

Purpose of This Addendum

Blockchain technologies introduce data considerations that traditional e-commerce and consulting privacy policies do not fully address. Public blockchain ledgers are immutable, openly viewable, and outside of any single party's control. When clients pay Block9 in cryptocurrency or interact with third-party blockchain applications based on Block9's recommendations, additional context applies. This Addendum explains how Block9 handles those situations and what clients
should understand before engaging.

Block9's Role in Blockchain Interactions

Block9 is a technology consulting and education company. We do not custody, hold, transmit, or have access to client funds, private keys, seed phrases, or wallet credentials at any time. We do not act as a money transmitter, exchange,
broker-dealer, or custodian. Clients execute all on-chain transactions
themselves.

Block9's involvement with on-chain activity is limited to:

•  Providing a Block9-controlled wallet address to receive a peer-to-peer payment for a Block9 invoice.

• Recording the on-chain transaction identifier alongside the corresponding invoice for accounting and confirmation purposes.

• Educating, configuring, or guiding clients on how to perform actions on their own wallets, nodes, or applications.

Block9 does not transact on behalf of clients, does not connect wallets to client identities for purposes other than confirming payment for a specific invoice, and does not maintain blockchain analytics on its clients.

Cryptocurrency Payment Data

When a client pays Block9 by sending Bitcoin or other supported cryptocurrency peer-to-peer to a Block9-provided wallet address, the following information may be associated with the client's account or invoice:

• The wallet address Block9 provided to receive the payment.

• The on-chain transaction identifier (transaction hash).

• The amount received and the date and time of confirmation.

• The USD-equivalent value of the payment at the time of receipt, recorded for accounting and refund-calculation purposes.

Block9 may treat this information as personal information under the CCPA and similar laws to the extent it can be associated with an identifiable individual through Block9's records. Block9 does not perform on-chain analytics, address
clustering, or similar tracing on client wallets.

Public Blockchain Data

Public, immutable, and outside Block9's control. Transactions on public blockchains such as Bitcoin and Stacks are recorded on open ledgers that anyone in the world can view. Wallet addresses, transaction amounts, timestamps, and the relationships
between addresses are publicly visible by design. Once a transaction is
broadcast and confirmed, it cannot be deleted, altered, anonymized, or
restricted. No party — not Block9, not the wallet provider, not the recipient,
not any government — can remove information from a public blockchain.

This has several practical consequences for client privacy:

• Anyone who knows your wallet address can view its transaction history.

• If you reuse a wallet address across multiple transactions, those transactions can be linked.

• Privacy rights such as the CCPA “Right to Delete” do not extend to data that has been recorded on a public blockchain. The right applies to the records Block9 itself keeps; it does not (and cannot) reach the blockchain itself.

• Best practices such as using fresh receiving addresses for each transaction, separating wallets used for different purposes, and avoiding linking your wallet address to your real-world identity in public forums are the responsibility of the individual user.

Third-Party Blockchain Applications

Block9 may recommend, demonstrate, or assist clients in configuring third-party blockchain applications, including wallet software, hardware wallets, blockchain explorers, decentralized finance protocols, and other tools listed on our resources page at www.block9.app/pages/resources.

When a client uses one of these applications, the client interacts directly with that application's provider and, in many cases, directly with a public blockchain. Any personal information shared with that application (account details, wallet addresses, transaction details) is collected and processed by that application's provider under its own privacy policy. Block9 does not control,
audit, or have any role in those data flows.

Block9 may receive limited referral or analytics information when a client clicks an affiliate link from www.block9.app to a partner platform, as described in the
main Privacy Policy. Block9 does not receive ongoing data about a client's
activity within third-party applications.

Effect on Individual Privacy Rights

Where applicable law (such as the CCPA) grants individuals rights over their personal information — including rights to know, delete, correct, opt out of sale or sharing, and limit use of sensitive personal information — those rights apply to the personal information Block9 itself collects and controls. They do not,
and cannot, apply to:

• Data recorded on a public blockchain.

• Data held by third-party blockchain applications, exchanges, or wallet providers, which is governed by those parties' own policies.

• Data Block9 is required to retain for legal, tax, accounting, or anti-fraud purposes.

Block9 will respond to verified individual rights requests in accordance with the main Privacy Policy and the California Privacy Notice. The blockchain-specific
limitations described in this Addendum do not waive or reduce any rights that
apply to data Block9 itself controls.

Client Responsibilities

Clients are responsible for taking reasonable steps to protect their own blockchain-related privacy and security, including:

• Securing seed phrases, private keys, and recovery materials. Block9 will never ask for these.

• Verifying any wallet address provided for a Block9 invoice through a separate communication channel before sending funds.

• Reviewing the privacy policies of any third-party blockchain application before using it.

• Understanding that on- chain transactions cannot be reversed by Block9 or anyone else once broadcast and confirmed.

Related Policies

This Addendum should be read alongside the Block9 Privacy Policy, the Block9 California Privacy Notice, and the Block9 Terms of Service, all available at
www.block9.app. In the event of an apparent conflict between this Addendum and the main Privacy Policy on a blockchain-specific topic, this Addendum controls. On all other topics, the main Privacy Policy controls.

Changes to This Addendum

Block9 may update this Addendum from time to time to reflect changes in our practices, the technology, or applicable law. The current version is posted at www.block9.app with the Effective Date and Last Updated dates noted at the top of this document.

Contact

Privacy and data requests: privacy@block9.app

General inquiries: sales@block9.app

Phone: (636) 224-8069

Mailing address: Block9 LLC, Attn: Privacy, PO Box 2, Barnhart, MO 63012, USA

Web: www.block9.app