Payment Proofs

Monero hides your transactions from the public by default — which raises a practical question. If a merchant claims your payment never arrived, or you need to show you paid an invoice, how do you prove it without exposing your entire financial life? The answer is the payment proof: a targeted, cryptographic way to demonstrate a single payment while keeping everything else private. In this lesson you will learn the main proof types and when to use each.

The Problem Proofs Solve

On a transparent chain, "proof" is trivial and total — anyone can see everything, all the time. Monero rejects that bargain. Because stealth addresses, ring signatures, and RingCT hide the parties and amounts, you need a deliberate mechanism to reveal just one fact to just one person. That is exactly what payment proofs provide: selective, opt-in disclosure that you control.

The Transaction Secret Key (Spend Proof)

When your wallet builds a transaction, it generates a one-time transaction secret key (often called the tx key) tied to that specific transaction. To prove you sent a payment, you share three things with the person who needs to verify:

• The transaction ID.
• The destination address you paid.
• The transaction secret key for that transaction.

With these, the recipient's wallet (or any wallet) can confirm that this exact transaction sent that exact amount to that exact address — without revealing your wallet, your balance, or your other transactions. This is the classic way a customer proves to a merchant that they really paid.

Proofs Your Wallet Can Generate

Modern Monero wallets streamline this into a few ready-made proof types you can produce with a click:

• TxProof (spend proof for a recipient) — proves a specific transaction paid a specific address a specific amount. Ideal for showing a merchant you paid them.
• SpendProof — proves that you were the sender of a given transaction, without revealing the destination, useful when you only need to prove authorship.
• Reserve proof — proves you control at least a certain amount of funds in your wallet at a point in time, without revealing your full balance or moving anything. Handy for showing solvency.

Each proof is a small text blob you hand to the verifier; they paste it into their wallet's "check" function to validate it. Nothing about your wider wallet is exposed.

The View Key as an Auditing Tool

For ongoing transparency rather than a one-off proof, you can share your private view key. It lets the holder see all incoming funds to your wallet but never spend them. This is the basis of a watch-only wallet and is perfect for accountants, charities proving donation receipts, or auditing — though remember it reveals your incoming history, so share it only deliberately.

Choosing the Right Proof

1. "I paid this merchant." Use a TxProof (transaction secret key, tx ID, and address).
2. "I sent this transaction." Use a SpendProof.
3. "I have at least this much." Use a reserve proof.
4. "Audit all my incoming funds ongoing." Share a view key (a bigger disclosure — choose carefully).

These tools tie directly into checking your transactions and into safely paying with Monero, where proving a payment can resolve disputes.

The official user guides include step-by-step instructions for generating and checking each proof type.

A Word of Caution

Every proof is a disclosure. A tx key reveals one payment; a view key reveals your whole incoming history. Share the minimum needed for the situation, and never hand over your spend key or seed phrase — those are not proofs, they are total control of your funds.

Payment proofs are Monero privacy turned inside out exactly when you want it: precise, voluntary transparency without surrendering your wallet. Master them and you can transact privately yet still settle disputes with confidence. Next, let's put it all into practice in Paying With Monero.