Documentary evidence of the origin of the money used in a specific transaction, distinct from source of wealth, which addresses the origin of the payer’s overall assets. The question is asked about one payment, not about a person’s finances in general. It is answered with records that trace that payment back to an identifiable event — a salary, a disposal, a distribution, a business receipt — and that someone other than the payer can check. A payer’s own account of where the money came from is where the enquiry begins, not where it ends. The term is abbreviated SOF, and the request usually arrives worded as proof of source of funds.
Source of funds, source of wealth, proof of funds
Three questions, routinely collapsed into one. They take different evidence and are asked at different moments.
| Question it answers | What evidences it | When it is asked | |
|---|---|---|---|
| Source of funds | Where the money in this transaction came from | Records tracing this payment back to an identifiable originating event | On any material transaction; always where enhanced due diligence applies |
| Source of wealth | How the payer’s assets were accumulated in the first place | Career, business, disposal and inheritance history, corroborated against public and independent records | Enhanced due diligence: politically exposed persons, high-risk profiles, wealth that does not match the profile |
| Proof of funds | That the money exists and is available now | A dated bank confirmation or statement | Before a seller commits capacity, an allocation or an exclusivity period |
The collapse has a cost, and it is the commonest reason a request is repeated. A payer who answers a source-of-funds request with a wealth narrative — career, holdings, standing — has supplied nothing about the specific money. A payer who answers with a balance certificate has proved the money exists and said nothing about where it came from. Both files come back.
When the question is asked
Under the FATF standards, customer due diligence extends to the source of funds where the transaction or the risk warrants it, and enhanced due diligence makes it mandatory rather than discretionary. In practice the trigger is one of five: a first payment on a new relationship; a transaction size out of proportion to the known profile; an occasional transaction above the applicable threshold; a link to a higher-risk category or jurisdiction; or an inconsistency between what the payer has said and what the account shows.
In a purchase of goods, two enquiries run in parallel and payers habitually confuse them. The seller asks because it is required to know its counterparty before accepting an instruction. The seller’s bank asks the seller, because a large incoming credit on a commercial account is itself a reviewable event. Satisfying the first does not satisfy the second: the seller needs the origin of the money, the bank needs the origin of the credit and the commercial reason for it.
What counts as evidence
The operative standard is corroboration, not volume. Several independent items that agree with each other carry more weight than one comprehensive document authored by the payer. What a reviewer weighs is independence and contemporaneity: who produced the record, and whether it was produced at the time of the event or afterwards for this purpose.
| Origin | Primary evidence | Where the chain usually breaks |
|---|---|---|
| Employment income | Payslips, employment contract, credit history on the receiving account | Accumulation over years across accounts since closed |
| Business proceeds | Audited accounts, dividend or distribution resolutions, corporate account statements | The step from company to shareholder is undocumented |
| Sale of an asset — property, shares, a business | Sale contract, completion statement, the settlement credit itself | Proceeds routed through an intermediate account before arriving |
| Inheritance or gift | Grant of probate, will, executor’s letter, deed of gift | The estate distributed years earlier, with no trace into the present account |
| Loan or facility | Facility agreement, drawdown advice | Related-party lending with no written facility |
| Disposal of digital assets | Platform conversion record, screening outcome, settlement advice | The acquisition record, not the conversion record |
Where original documents cannot be produced, because the transaction is old or the institution no longer exists, the standard is not waived. It is met by an accumulation of individually weak items that point the same way — a pattern of credits, a third-party confirmation, a contemporaneous filing.
What changed in 2025 and 2026
Four developments in eighteen months have shifted what a source-of-funds file has to survive. None of them changes the definition; all of them change what the evidence is checked against.
Reported crypto data now exists independently of the payer. Under the OECD’s Crypto-Asset Reporting Framework, crypto-asset service providers in the largest group of committed jurisdictions began collecting reportable user and transaction data on 1 January 2026, with first automatic exchanges targeted for 2027 covering 2026 activity. As of July 2026, 76 jurisdictions were formally committed; a later group, including Singapore, the United Arab Emirates, Switzerland and the United States, is due to exchange by 2028. The European Union implements through DAC8, and the amended Common Reporting Standard extends to e-money and certain tokenised products. The consequence for a source-of-funds file is direct: a payer’s account of a digital-asset disposal is now checkable against a dataset the payer neither authors nor holds.
Payment messages are becoming structured identity. The FATF revised Recommendation 16 at its June 2025 plenary and retitled it Payment transparency. The revision reaches beyond wire transfers to payments and value transfers generally, requires structured data in line with established messaging formats, obliges intermediary institutions to keep that data intact along the chain, and requires beneficiary institutions to run alignment checks against misdirected payments. Where the originator or beneficiary is a legal person, the accompanying information is to include a connected business identifier code, a Legal Entity Identifier, or the entity’s unique official identifier. Countries are expected to be ready by the end of 2030; an assessment annex followed in October 2025 and implementation guidance went to public consultation in June 2026. For a corporate counterparty the practical effect arrives before the deadline: the identity travelling with a payment becomes a structured field rather than a free-text name, and a mismatch between the contracting entity, the invoiced entity and the paying entity stops being a clerical matter.
Blanket refusal is now out of step with the standard. In February 2025 the FATF revised Recommendation 1 and its interpretive note, replacing commensurate with proportionate and formalising simplified measures in lower-risk situations, with corresponding amendments to the notes on customer due diligence and on new technologies. Guidance followed in June 2025 treating exclusion as a problem in its own right rather than a safe default. The FATF’s own sector guidance on the risk-based approach for dealers in precious metals and stones now carries an explicit notice that it does not reflect the 2025 revisions to Recommendation 1 and must be read with the newer material. A counterparty citing that guidance is citing a document its author flags as behind the current standard.
In the European Union the questions converge. Regulation (EU) 2024/1624 applies from 10 July 2027 and brings dealers in precious metals and stones into scope as obliged entities directly, rather than through twenty-seven national transpositions, alongside an EU-wide limit of €10,000 on cash payments. After that date the enquiry a European counterparty runs is the same enquiry in every member state.
The four point the same way. Source of funds is moving from a bundle of documents the payer selects toward a set of records held by others, in structured form, against which the payer’s version is tested.
Source of funds where the money originates in digital assets
The chain has four parties and each produces one part of the file. The payer instructs. A licensed digital-asset platform screens the wallet and the transaction under its own licence, converts, and settles in national currency. Golden Ark Reserve receives fiat only, holds no digital assets, and issues no token or claim on metal. A single order reference binds quote, pro forma invoice for advance payment, incoming payment, settlement, allocation and the resulting document set to one instruction.
What that produces for a bank enquiry is an acquisition history held on the platform, a screening outcome, a conversion record showing assets in and currency out at a stated rate and time, and a settlement advice carrying the order reference. What it does not produce is any statement by the seller about the payer’s tax position or the lawfulness of the acquisition. Those are not the seller’s to make and a file that implies otherwise reads worse, not better.
The weak link is acquisition, not conversion. Assets bought years ago, self-custodied, or held on a platform that has since closed leave the conversion leg immaculately documented and the origin leg empty. Analytics on the chain can establish that an address carries no exposure to sanctioned or illicit sources; it cannot establish that whoever controls that address paid for the assets out of income that was itself accounted for. Reviewers ask both questions and treat an answer to the first as an answer to the first only.
What a documented purchase puts on the file
An instruction that completes produces a fixed set of records: the sale-and-purchase agreement, the AML/KYC record, payment confirmation, the Allocation Record identifying each bar by serial number, weight, fineness, producer and location, the vault placement or delivery documentation, and the instruction log. Metal sits in a dedicated client sub-account at Brink’s Hong Kong or Singapore, named to the counterparty in the vault register and segregated from Golden Ark Reserve’s own stock; custody is coordinated through Brink’s rather than held by the seller. Banking and settlement counterparties behind that chain are described at Banking & Insurance Partners.
Four different parties attest to those records — the platform, the bank, the seller, the vault operator. That is what makes the set corroborative rather than self-reported, and it is the property that survives a review months later.
How source-of-funds files fail
Reconstructed after the fact. The single most common failure. A payer assembles the file when the bank asks, months after the payment, from screenshots and recollection. The operator that screened and converted at the time produces its record at the time; it does not reissue one to order afterwards. What existed at the moment of the transaction is what the file can contain.
No binding reference. A payment arriving without a reference is an unattributed credit: it cannot be matched to an instruction at the moment of receipt, and the match is later argued from correspondence rather than read off the payment.
A payer who is not the counterparty. Money arriving from an account in a different name than the contracting party opens a second source-of-funds enquiry into the third party, and closes nothing.
Name drift. Contract, invoice and payment instruction carrying three variants of the same legal name. Under the revised payment-transparency standard this becomes machine-detectable rather than a matter of clerical tolerance.
Complete but self-authored. A long, coherent, entirely payer-produced narrative with no independent item in it. Reviewers read corroboration, not fluency.
The wrong question answered. A wealth narrative, or a balance certificate, in answer to a request about one payment.
The purchase record is the next transaction’s source of funds
Source of funds is normally treated as a gate at the door. In a physical-asset transaction it is also something the transaction produces, and the record made at the gate becomes the provenance every later party reads.
A documented bullion purchase closes one source-of-funds question and opens another, years out. When the bars are sold back, the proceeds arrive in the counterparty’s bank account as a large credit from a commercial seller in a free zone — exactly the profile that triggers an enquiry. What answers it is the purchase file: the agreement, the pro forma and the commercial invoice issued against actual allocated bars, the Allocation Record naming those bars by serial, the placement confirmation, and the buyback settlement advice. Read together they trace the money from an identifiable origin, through metal identified by serial number, back into the banking system, with each step attested by a party with no interest in the next one.
That makes the completeness of the purchase record an evidentiary question rather than an administrative one, and it makes the moment to answer it the moment of purchase. Reported crypto data and structured payment messages sharpen it further: where a file is tested against records held by others, a contemporaneous set bound by one reference survives the test and a narrative assembled afterwards does not. A counterparty who accepted a thin file on the way in discovers the gap on the way out, when the party that could have closed it is no longer in the chain.
The controls applied before an instruction is accepted, and the documents produced against it, are set out in AML/KYC Policy.