Supporting document summaries and AI data leakage: what payslips and bank statements give away in ChatGPT or Claude.

Summarising a client’s payslips, bank statements and identity scans is the most repetitive job in broking, and the one most often handed to ChatGPT or Claude. The summary is dense: salary and tax figures, balances, the pattern of every payment, credit scores, and the discrepancies the broker has spotted. The statements can also show where a family spends: a health practitioner, a relative, a school. This page marks every item in a routine supporting documents summary that the National Consumer Credit Protection Act and the Privacy Act bear on, and shows how the same summary is produced on Ermos inside the brokerage.

The supporting documents summary

Compiled when the client’s documents arrive, so that the broker can take the reasonable steps to verify the consumer’s financial situation that section 117 of the National Consumer Credit Protection Act requires, and so that the file shows what was seen and when.

Supporting documents summary
Whitlock, D & S · received 14 October 2026 · checked by AM, 3.20pm

Identity	Daniel: NSW driver licence 00000000, expiry 11 June 2029, original sighted and scanned. Sophie: Australian passport N0000000, expiry 2 March 2031, original sighted and scanned.¹
Payslips	Daniel (Brightline, fortnightly), 9 October: gross $6,258 including $412 overtime, net $4,535. Sophie (Riverbend), 8 October: gross $3,231, net $2,551. Three payslips each, year-to-date figures consistent.²
Employers	Brightline letter of 12 October confirms permanent full time from 17 November 2025 (contact Marcia Thorne, payroll). Riverbend letter confirms permanent 0.8 FTE.³
Bank statements	Joint CBA Everyday ending 7733, 90 days to 12 October: salary credits average $15,310 a month, balance $7,500. ING Savings Maximiser ending 4821: $271,800, including $60,000 received from G Pryor on 9 October.⁴
Spending seen	Regular debit of $220 a fortnight to Dr Alana Iyer, Psychologist (Sophie).⁵ Transfer of $400 a month to Margaret Pryor (Sophie’s mother), described as help with her rent.⁶
Credit reports	Daniel: score 812, one 14-day late payment on the Visa in January 2026, no other enquiries in 12 months. Sophie: score 861, no adverse listings, no other enquiries.⁷
Discrepancies	Payslip shows “Danny Whitlock”; Brightline to confirm legal name. Declared living expenses $5,150 against $5,350 average in statements.⁸
Gift	Gift letter from Gerald Pryor dated 9 October: $60,000, no repayment, funded from the sale of a rental property in Bathurst. Sophie’s mother does not know the amount.⁹
Still to come	Contract of sale once exchanged, bank valuation, final payslip before settlement.¹⁰

An invented summary. Licence and passport values are placeholders; account endings are invented. Hover or tap any highlighted item for the analysis; the full list is below.

What leaves the brokerage

Identity documents

Document numbers, expiry dates and the fact that originals were sighted. The identifiers used to verify two people, and the material identity theft is built from. Privacy Act guide.

Frontier Models (ChatGPT, Claude)	Two sets of identity numbers transmitted, generally offshore on personal plans
Ermos Edge	Stays on your instance in Australia; leaves only inside a permitted excerpt, per question, to the named provider
Ermos Dominion	Stays on the unit in your office

Payslip figures

Gross, net, overtime and year-to-date pay for two people. The verification of the consumer’s income that section 117 requires, in a form that discloses it. Privacy Act guide.

Frontier Models (ChatGPT, Claude)	Pay figures for two people transmitted
Ermos Edge	Stays on your instance in Australia; leaves only inside a permitted excerpt, per question, to the named provider
Ermos Dominion	Stays on the unit in your office

Employers and a named payroll contact

Confirmation of permanent status and a named person at an employer. Employment information about the clients, and a third person’s name. Privacy Act guide.

Frontier Models (ChatGPT, Claude)	A named payroll contact transmitted
Ermos Edge	Stays on your instance in Australia; leaves only inside a permitted excerpt, per question, to the named provider
Ermos Dominion	Stays on the unit in your office

Account balances and endings

Salary credits, balances, account endings and the source of a large deposit. A complete picture of a household’s liquid position. Privacy Act guide.

Frontier Models (ChatGPT, Claude)	Balances and account endings transmitted
Ermos Edge	Stays on your instance in Australia; leaves only inside a permitted excerpt, per question, to the named provider
Ermos Dominion	Stays on the unit in your office

A health practitioner in the statements

A recurring payment to a named psychologist. A payment like this can reveal that a person is receiving a health service, and health information is sensitive information under the Privacy Act, with stricter rules. Patient data guide.

Frontier Models (ChatGPT, Claude)	A health service revealed by a bank line, transmitted
Ermos Edge	Stays on your instance in Australia; leaves only inside a permitted excerpt, per question, to the named provider
Ermos Dominion	Stays on the unit in your office

Support for a relative

A regular transfer to a named person and its stated purpose. A third person’s circumstances, revealed by someone else’s bank statement. Privacy Act guide.

Frontier Models (ChatGPT, Claude)	A relative’s circumstances transmitted
Ermos Edge	Stays on your instance in Australia; leaves only inside a permitted excerpt, per question, to the named provider
Ermos Dominion	Stays on the unit in your office

Credit reports

Scores, a late payment and enquiry counts for two people. Credit reporting information is regulated by Part IIIA of the Privacy Act, which also limits who may obtain it (section 24); how a brokerage obtained a report governs what it may do with it. Privacy Act guide.

Frontier Models (ChatGPT, Claude)	Credit scores and enquiries transmitted
Ermos Edge	Stays on your instance; how the reports were obtained still governs what you may do with them
Ermos Dominion	Stays on the unit; how the reports were obtained still governs what you may do with them

Discrepancies the broker spotted

A name mismatch and declared against actual spending. The broker’s verification work, and the kind of mismatch fraud checks look for. Privacy Act guide.

Frontier Models (ChatGPT, Claude)	Your verification findings transmitted
Ermos Edge	Stays on your instance; spotting the mismatch is the broker’s check, and a model can miss it
Ermos Dominion	Stays on the unit; spotting the mismatch is the broker’s check, and a model can miss it

The gift letter

A relative’s gift, its source and a family secret. A third person’s financial affairs and a confidence between spouses and parents. Privacy Act guide.

Frontier Models (ChatGPT, Claude)	A relative’s gift and a family secret transmitted
Ermos Edge	Stays on your instance in Australia; leaves only inside a permitted excerpt, per question, to the named provider
Ermos Dominion	Stays on the unit in your office

10
Outstanding items
A generic list of documents still to come. Low exposure alone.

Frontier Models (ChatGPT, Claude)	A generic list of documents; low exposure alone
Ermos Edge	Nothing sensitive to keep in
Ermos Dominion	Nothing sensitive to keep in

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 brokerage 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 client 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 Edge	Ermos Dominion
Where the document is processed	Provider servers, generally offshore on personal plans	Your instance in an Australian data centre; answers generated in Australia	The unit in your office
Who can read it	Provider staff and systems, under policy	Your staff, within the boundaries you set. The named Australian provider processes only permitted excerpts, under contract, and keeps nothing	Your staff only
Is it kept	On the provider’s terms	Kept on your instance; the provider is barred from retaining it	Stays on the unit
Can it train a model	On consumer tiers, yes	No, by contract	Only your own unit learns from it, on your hardware

Part of AI data leakage in mortgage brokerages. See how this works in practice: Documentation best practice on Ermos.

Common questions

Do ChatGPT and Claude use the information in a supporting documents summary?

Anything pasted from the summary 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. The summary lists licence and passport numbers, payslip figures, account endings and a recurring payment to a named psychologist.

Can we use ChatGPT or Claude for a supporting documents summary if we remove the names?

No, because the details in the summary identify the household without the names. 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. A salary pattern, a payroll contact at an employer, a named psychologist and a monthly transfer to a relative fit one family. The payment to the psychologist can reveal a health service, and health information is sensitive information under the Privacy Act. 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.

Does deleting the chat remove a supporting documents summary from ChatGPT or Claude?

No, deleting the chat does not prove the summary is gone. Deleting a chat removes it from the user's history, but OpenAI and Anthropic each say they can keep a deleted chat on their systems for up to 30 days, and longer where safety or legal obligations apply (OpenAI, Anthropic). 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). A summary pasted for a quick check carries two identity documents, credit reports for two clients and a gift letter that records a family secret, so the brokerage could not show the clients those details have gone.

How can a mortgage brokerage use AI for a supporting documents summary 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 summary is drafted from the documents on the client file and the brokerage's own summary template. The broker checks each entry against the originals sighted and signs it.

What does verification mean for a broker?

Section 117(1)(c) of the National Consumer Credit Protection Act requires the licensee to take reasonable steps to verify the consumer's financial situation, and section 118(4) says only information the licensee had reason to believe was true, or would have had reason to believe if it had verified, counts in assessing unsuitability. The summary is the record of the verification done.

Can a bank statement contain sensitive information?

Yes. The Privacy Act treats information about a person's health, including health services provided to them, as sensitive information. A recurring payment to a named practitioner can reveal that. Financial information such as balances and incomes is personal information rather than sensitive information, but a statement can carry both.

Are credit reports covered by their own rules?

Yes. Part IIIA of the Privacy Act regulates credit reporting information and credit eligibility information, and section 24 makes it an offence and a civil penalty matter to obtain credit reporting information from a credit reporting body when the entity is neither one the body may disclose it to under Division 2 of Part IIIA nor an access seeker for the information. A brokerage should follow the terms on which it obtained each report.

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