Buyer offer emails and AI confidentiality: what an offer email gives away in ChatGPT or Claude.

When a buyer makes an offer, the sales agent writes to the vendors straight away and wants the email to be clear, calm and persuasive. Asking ChatGPT or Claude to polish it is an obvious shortcut. The email carries the offer figure, the buyers’ names, their finance and how they will fund the deposit, the reason they are in a rush, who else is interested and what the agent advises. This page marks every item in a routine offer email and shows how the same email is drafted on Ermos inside the agency.

The buyer offer email to a vendor

Sent to the vendors on the day an offer is received. NSW Fair Trading says an agent acts for the vendor and must act honestly and in the client’s best interests.

From:
To: Ross and Helen Carmody
Date: Wednesday 28 October 2026, 4.40pm
Subject: 27 Elsmere Avenue: pre-auction offer

Dear Ross and Helen,

I have received an offer on the house this afternoon from , who came through the second open home on 17 October.

The offer.

Their finance.

Their position.

Other interest.

My advice.

The auction stays on for . Please call me tonight or in the morning.

Kind regards,
Marcus

An invented offer email. People, streets and telephone numbers are fictional. Hover or tap any highlighted item for the analysis; the full list is below.

What leaves the agency

  1. 1
    The buyers

    Two named people and the open home they attended. Personal information about people who are not the agency’s clients. Privacy Act guide.

  2. 2
    The offer and its conditions

    The price, the deposit, the settlement period and the deadline. Commercial information that matters most to the vendors and most to a competing buyer.

  3. 3
    The buyers’ finance and the source of the deposit

    A lender pre-approval, the sale of a unit and a family gift. Financial information about the buyers, collected to show the offer is genuine. Privacy Act guide.

  4. 4
    Personal circumstances and the buyers’ ceiling

    A pregnancy and a due date, the urgency that follows, and a remark about how far they could go. Health information is sensitive information under the Privacy Act where the Act applies, and the ceiling is what the buyers would least want a rival to know. Patient data guide.

  5. 5
    Other buyers’ details

    Two other buyers named, with their cash position and what they are waiting on. Their information, shared outside the conversation they thought they were having. Privacy Act guide.

  6. 6
    The agent’s advice and the vendors’ bottom line

    A recommended counter and the figure the vendors said they could accept. The agent acts for the vendors, and NSW Fair Trading says agents must act in their clients’ best interests.

  7. 7
    The auction date and time

    Public as soon as the campaign is advertised, so sending it exposes nothing the listing does not already show.

  8. 8
    The agent’s contact details

    A mobile number and the agency. Business contact details that are public already.

  9. 9
    The agent

    Ties the email to a named agent working for the agency.

What happens in Frontier Models (ChatGPT, Claude)

  • The whole document is transmitted to the provider’s servers. On personal plans the user cannot choose where it is stored or processed, and for the major providers that has generally meant outside Australia, under that country’s legal process. Some business plans offer storage in Australia, but the provider still receives the content.
  • On consumer tiers, prompts can be retained and used to train future models.
  • The provider’s staff and systems can reach the content under the provider’s own policies.
  • Once sent, the agency no longer controls it. Retention and deletion happen on the provider’s terms.

The same document on Ermos

Ermos Dominion

The document is drafted on a unit in your office, from your own templates and the property file. Every marked item stays on the unit, which keeps working with the internet switched off. Nothing in it is transmitted to an AI provider, so there is no disclosure to analyse: the confidentiality work is the same as for your file server.

Ermos Edge

Your documents, the index and your access boundaries stay on your own instance in an Australian data centre. When a staff member asks for this draft, only their question and the excerpts they are permitted to see go to a named Australian provider, who is contractually barred from keeping the content or training any model on it. Nothing is processed outside Australia.

Frontier Models (ChatGPT, Claude)Ermos EdgeErmos Dominion
Where the document is processedProvider servers, generally offshore on personal plansYour instance in an Australian data centre; answers generated in AustraliaThe unit in your office
Who can read itProvider staff and systems, under policyYour staff, within the boundaries you set. The named Australian provider processes only permitted excerpts, under contract, and keeps nothingYour staff only
Is it keptOn the provider’s termsKept on your instance; the provider is barred from retaining itStays on the unit
Can it train a modelOn consumer tiers, yesNo, by contractOnly your own unit learns from it, on your hardware

Part of AI data leakage in real estate agencies.

Common questions

Do ChatGPT and Claude use the information in a buyer offer email?
A pasted email goes to the AI company's servers and is processed there to produce a reply. As at October 2026, whether a conversation on a personal plan (ChatGPT Free, Plus or Pro; Claude Free, Pro or Max) can be used to train the models depends on a setting each user controls. Business plans (ChatGPT Business and Enterprise, Claude Team and Enterprise) and the developer APIs sit under commercial terms, and OpenAI and Anthropic each say they do not train on that content by default (OpenAI, Anthropic). On either product, the thumbs up and thumbs down buttons can send a whole conversation back for training. This email holds the Lindqvists' offer of $1,865,000, their pre-approval, a baby due in December and the agent's advice to the vendors on a counter.
Can we use ChatGPT or Claude for a buyer offer email if we remove the names?
Not safely, because the circumstances still identify the buyers. Removing names rarely makes a document anonymous. Information stays personal information while the person is reasonably identifiable, and the OAIC warns that information can be at risk of re-identification even when it has been de-identified or anonymised. A pre-approval of $1.9 million, the sale of a Marrickville unit, a gift from a parent and a baby due in December describe one couple, and the email also names two other interested buyers. The Office of the Australian Information Commissioner (OAIC) recommends in its guidance on commercially available AI products that organisations do not enter personal information, and particularly sensitive information, into publicly available generative AI tools, because of the significant and complex privacy risks.
Can ChatGPT or Claude remember the details in a buyer offer email later?
They can. Both products also have memory features that can carry details from one conversation into later ones, and on a personal account each user decides whether they are switched on (ChatGPT, Claude). An agent who drafts offer emails in one account could find a buyer's finance and ceiling, and the $1.92 million the vendors said they could accept, following the user into a later chat about a different listing. Those details were shared for one sale.
How can a real estate agency use AI for a buyer offer email without sending it to ChatGPT or Claude?
Ermos is built so the document stays under your control. On the Dominion AI unit it is drafted inside your office and none of it is sent to an AI provider. On Ermos Edge your documents and index stay on your own instance in an Australian data centre, and only the question and the excerpts the user is permitted to see go to a named Australian provider that is contractually barred from keeping them or training any model on them. The email is drafted from the property file and the agency's own email template. The sales agent checks the offer terms and the advice against the file, then signs it off.
Who does the sales agent act for when an offer comes in?
The vendor. NSW Fair Trading says agents must act in the best interests of their clients, honestly, fairly and professionally, and must declare conflicts of interest. What a buyer tells the agent, such as how far they could go, is information about an identifiable person, and sending it to an AI provider is a separate disclosure.
Is a buyer's pre-approval or deposit information personal information?
Yes. A lender pre-approval, a gift from parents and the proceeds of a sale are financial information about identifiable people. Whether the Privacy Act binds a particular agency depends on its turnover and activities, and the OAIC says a small business that is a reporting entity under the AML/CTF Act is covered only for its AML/CTF activities.
What does the agent have to tell a buyer who has paid an expression of interest deposit?
NSW Fair Trading's rules of conduct page says an agent acting for the vendor must promptly inform the person if a subsequent offer is made, and must promptly tell the client that an expression of interest deposit has been paid. Those duties apply whoever drafts the email.

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