The 5W framework for SAR writing, good vs bad examples, the most common mistakes MLROs make, typologies that need specific information, and how to write a SAR that becomes actionable intelligence.
The UK receives more SARs per capita than almost any other country in the world. Yet the UKFIU and NCA have consistently flagged the same problem: too many SARs provide too little actionable intelligence. A defensive SAR, filed to avoid prosecution, with minimal content, vague language, and incomplete subject information, consumes UKFIU analyst time without contributing to law enforcement outcomes.
The difference between a good SAR and a bad one is not the length: it is the specificity, the clarity of reasoning, and the completeness of the information provided. This part of the guide teaches you to write SARs that get used.
"What we need is not more SARs. We need better ones. A SAR that tells us who, what, why it's suspicious, and gives us something to work with is worth fifty defensive filings that tell us nothing useful."
Section 01
The 5W framework: the backbone of every SAR
Every SAR, regardless of the typology or complexity, should answer five fundamental questions. These are the intelligence questions that the UKFIU analyst needs to begin an investigation.
Who
Subject
Full identity of the subject: name, DOB, address, account numbers, national IDs, business connections
What
Activity
Precisely what happened: transaction amounts, dates, accounts, counterparties, payment references
Why
Suspicion
Why is this suspicious? The reasoning: not just a description of events but why they indicate ML/TF
When
Timeline
Dates and times: when did the activity occur, when was it identified, what is the relevant period
Where
Geography
Jurisdictions, accounts, institutions, addresses involved, particularly any cross-border elements
Before submitting any SAR, ask yourself: does this report clearly answer all five questions? If any are missing or vague, the SAR needs more work before it is submitted.
Section 02
Subject information: be exhaustive
The most common quality failure in SARs is inadequate subject information. The UKFIU cannot investigate a subject they cannot identify. Provide everything you know.
For individual subjects
Field
What to include
Priority
Full name
All names, including middle names and any known aliases or former names
๐ด Essential
Date of birth
Full DOB, not just year
๐ด Essential
Address
Current residential address, all addresses if multiple known
๐ด Essential
Account details
All account numbers, sort codes, IBANs associated with the subject
๐ด Essential
Nationality/passport
Nationality, passport number and issuing country if held on file
๐ก Important
Occupation
Stated occupation and employer, especially relevant if inconsistent with activity
๐ก Important
Phone/email
Contact details on file, useful for linking to other intelligence
๐ก Important
Associated persons
Named associates, joint account holders, related parties
๐ก Important
National insurance/tax ID
NI number or overseas tax ID if held
๐ข Include if known
For business/entity subjects
Full legal name and any trading names
Company registration number and registered address
Nature of business and stated purpose of relationship
Names and details of directors and ultimate beneficial owners
All account numbers associated with the entity
VAT number if known
Related entities in the same group or under common ownership
๐ก
Include what you know, even if incomplete
Do not delay submitting a SAR because you do not have all subject information. Include what you have and flag clearly what is unknown. An incomplete SAR submitted promptly is better than a complete SAR submitted late. The UKFIU can supplement SAR intelligence from other sources, but only if they have something to work with.
Section 03
Writing the narrative: the heart of the SAR
The narrative is the most important part of the SAR. It is where the MLRO explains the suspicious activity, sets it in context, and communicates why it gives rise to suspicion of money laundering or terrorist financing. A good narrative is clear, specific, logical, and reads like an intelligence report, not a compliance form.
Narrative structure: a recommended approach
Context: who is the customer, what is the relationship, what do you know about them? (2-3 sentences)
What happened: describe the suspicious activity specifically: dates, amounts, counterparties, accounts (as much detail as possible)
Why it's suspicious: explain why this activity is inconsistent with what you know about the customer, or why it matches a known ML/TF typology. This is the most important paragraph.
What you've done: any additional checks conducted: adverse media search, CDD review, customer contact (if appropriate)
What you need: if submitting a DAML, state clearly what consent you are seeking and the value/nature of the transaction
The key paragraph: why it's suspicious
Many SARs describe what happened without explaining why it's suspicious. The "why" is what makes your SAR actionable. Some examples of good "why" reasoning:
"This activity is inconsistent with the customer's stated occupation as a part-time teacher and declared income of ยฃ18,000 per year: the account has received ยฃ240,000 in the past 12 months."
"The pattern of deposits, multiple cash payments between ยฃ8,000 and ยฃ9,500 over a 30-day period, is consistent with structuring to avoid the firm's internal cash reporting threshold."
"The customer provided no explanation for the source of funds when asked, stating only that it was 'a business payment' despite having no registered business activity on file."
"The recipient account in Jurisdiction X has been associated with fraud in previous adverse media reporting identified during our checks."
Section 04
Good vs bad: real examples
The difference between a useful SAR and a defensive one is stark. These examples illustrate the quality gap.
Example 1: structuring suspicion
โ Poor SAR narrative
"Customer has been making multiple cash deposits. This is suspicious and we are reporting it. The customer has not provided a satisfactory explanation."
โ Strong SAR narrative
"Between 1 March and 30 April 2026, the customer made 14 cash deposits totalling ยฃ127,450. No individual deposit exceeded ยฃ9,500. The customer's stated occupation is retail shop assistant with declared income of ยฃ22,000 per annum. This pattern is consistent with structuring to avoid internal reporting thresholds. When contacted regarding the source of funds on 28 April, the customer terminated the call. No explanation has been provided."
Example 2: international wire suspicion
โ Poor SAR narrative
"Customer has sent funds internationally to a high-risk jurisdiction. We cannot verify the purpose of the transaction. Filing for compliance purposes."
โ Strong SAR narrative
"On 15 June 2026, the customer (John Smith, DOB 12/03/1978, Account 12345678) sent ยฃ85,000 to account [IBAN] at [Bank], [Country], a jurisdiction on the FATF grey list. The stated purpose was 'investment.' The customer has no declared business interests overseas and has not previously sent international transfers. The receiving account name does not match any known associate. An adverse media search conducted on 18 June returned results linking the account holder's name to a fraud investigation in [Country] reported by [news outlet] on [date]."
โ ๏ธ
Avoid vague "compliance purposes" SARs
The phrase "filing for compliance purposes" in a SAR narrative is a red flag that the MLRO is unsure whether they should be filing at all. If you cannot articulate why the activity is suspicious, consider whether the reasonable grounds threshold has actually been met. Filing defensively without genuine suspicion does not protect the firm, and poor quality SARs undermine the effectiveness of the entire regime. If in doubt, consult legal counsel before filing.
๐ก๏ธ Strengthen your SAR with screening data
Adverse media results can be cited directly in your SAR narrative
FinCrimeRadar's adverse media search returns BBC, OCCRP, AP and DW results, relevant findings can be cited to add intelligence value to your SAR.
Narrating what happened without saying why it's suspicious. Description โ intelligence.
Mistake 02
Missing subject details
Omitting DOB, address, account numbers, or aliases that are on file. Include everything you have.
Mistake 03
Late filing
Filing weeks after the suspicion arose. "As soon as practicable" means promptly, not after the next quarterly review.
Mistake 04
Vague amounts
"Large cash deposits" is useless. "14 cash deposits totalling ยฃ127,450 between March and April 2026" is intelligence.
Mistake 05
No DAML when needed
Filing a standard SAR when a transaction is pending, rather than seeking a DAML: if the underlying act independently meets the elements of a section 327, 328, or 329 offence with no defence or exemption applying, proceeding without a DAML leaves the firm exposed to that offence. Failing to seek consent does not itself create the offence.
Mistake 06
Generic typology
"This may be money laundering" without linking to a specific typology or explaining what ML methodology is suspected.
Mistake 07
No additional checks
Filing without first conducting adverse media searches, sanctions screening, or reviewing the full CDD file for relevant history.
Mistake 08
Not documenting non-files
Receiving an internal SAR report, deciding not to file externally, and leaving no record of the decision or reasoning.
๐ง Knowledge check
An MLRO receives an internal SAR about a customer making repeated cash deposits. After investigation, the MLRO decides NOT to file an external SAR because they believe there is an innocent explanation. What must the MLRO do?
Section 06
Typology-specific SAR tips
Different money laundering typologies require different information in the SAR narrative. Here are the key additions for the most common typologies:
๐ฆ Structuring / smurfing
List every deposit: date, amount, branch/channel, account credited
State the threshold that appears to be avoided (e.g. your internal cash reporting threshold)
Include the total amount deposited and the period over which it occurred
Compare to customer's declared income and account history
๐ Trade-based money laundering (TBML)
Name the specific goods or services ostensibly involved in the trade
Identify the over or under-invoicing indicators: compare invoice values to market rates
Name the counterparties and their jurisdictions
Flag any mismatch between the stated trade and the customer's known business activity
๐ Property-related laundering
Property address, purchase price, and any cash element
Source of funds for the deposit or purchase, if unknown or suspicious, say so
Any third-party payments or unusual settlement arrangements
Conveyancer/solicitor details if known
๐ป Cyber fraud / authorised push payment
The specific nature of the fraud if known (invoice fraud, romance scam, impersonation)
The receiving account details: sort code, account number, name of account holder
Whether the victim is the subject of the SAR (mule) or a third party
Any URLs, email addresses, or phone numbers associated with the fraud
๐ Cryptoasset-related
Wallet addresses associated with the activity
Which blockchain/network (Bitcoin, Ethereum, etc.)
Any exchange platforms used, named, if known
Results of any blockchain analytics checks conducted
Whether the wallet has been flagged by analytics tools as associated with illicit activity
Section 07
Frequently asked questions
Should we mention our screening tool results in the SAR? +
Yes, if your screening checks produced relevant results, include them in the SAR narrative. For example: "A sanctions screening check conducted on [date] against [source] returned a potential match for the subject against [list], this was investigated and [confirmed/not confirmed as a true match]." Or: "An adverse media search on [date] returned results linking the subject to [allegation/investigation] reported by [source] on [date]." This adds intelligence value and demonstrates the thoroughness of your investigation. Negative results are also worth noting: "Screening against OFAC, UN, EU, and OFSI lists returned no matches."
How long should a SAR narrative be? +
There is no prescribed length. A simple structuring SAR covering one customer and a clear transaction pattern might need 200-300 words. A complex SAR covering multiple related accounts, international transfers, and a suspected trade-based laundering scheme might run to 1,000 words or more. The principle is: include everything relevant, nothing irrelevant. The NCA does not reward length: it rewards precision and completeness. Every sentence should add intelligence value. Padding a SAR with general background information about money laundering typologies wastes analyst time.
Can we share information from one SAR with another reporting entity? +
Yes, with care, and only within narrow statutory limits. Section 333B and section 333C POCA create two separate, limited exceptions to the tipping-off prohibition, not one blended test. Section 333B covers specified disclosures within the same undertaking, within the same group of credit or financial institutions, or between professional advisers who share common ownership, management, or control. Section 333C covers a different scenario: disclosure between institutions or advisers of a matching type only (credit institution to credit institution, financial institution to financial institution, professional adviser to another adviser of the same kind), and only where all of the following apply together: the disclosure concerns a shared or former shared client, or a transaction or service involving both parties; it is made for the sole purpose of preventing an offence under Part 7 POCA; the recipient is situated in the UK, an EEA state, or a country imposing equivalent money laundering requirements; and both parties are subject to equivalent duties of professional confidentiality and data protection. These are known as "permitted disclosures." Neither section permits disclosure to any regulated-sector party generally, or for any AML/CTF purpose generally: the conditions are specific and cumulative. In practice, information-sharing arrangements between firms for SAR-related purposes should be documented and should be reviewed by legal counsel to ensure they fall within the permitted exceptions.