Secondary Identifiers in Sanctions Screening

Secondary identifiers in sanctions screening are the extra data points you use to confirm or clear a name match. A name alone rarely tells you enough. Thousands of people share the same name. Secondary identifiers like date of birth, nationality, and passport number let you decide if a hit is real or just a coincidence.

This guide explains what these identifiers are, where they come from, and how to use them. You will see how they cut false positives, what to do when they are missing, and how to record your decisions. If you screen customers, suppliers, or shipments, this is the detail that makes screening defensible.

What secondary identifiers are

A primary identifier is the name. It triggers the alert. A secondary identifier is any other field that helps you tell one person or company from another. Regulators publish these fields alongside each listed party so you can match with more certainty.

Think of it this way. The name gets you a possible hit. The secondary identifiers tell you whether the hit is your customer or a stranger who happens to share the name. Without them, you are guessing.

Sanctions lists carry a rich set of these fields. The OFAC SDN list shows dates of birth, places of birth, nationalities, passport numbers, and addresses for many entries. Other regimes publish similar detail. Your job is to compare your record against those fields.

The main types of secondary identifier

Identifiers split into two groups. Some point to a person. Others point to a company, a vessel, or an aircraft. Here is what each list entry can hold.

Subject	Common identifiers	Strength
Individual	Date of birth, place of birth, nationality, passport number, national ID, address, gender, title	Passport and national ID are strongest. Date of birth is strong. Nationality is weaker on its own.
Company	Registration number, tax ID, LEI, registered address	Registration number and tax ID are strongest. Address helps but can be shared.
Vessel or aircraft	IMO number, call sign, flag, tail number	IMO and tail numbers are stable and hard to fake.

Numbers beat text. A passport number or an IMO number is unique and stable. A name or address can be spelled many ways. So when a list entry carries a strong number and it matches your record, you have near certainty.

How identifiers reduce false positives

A false positive is an alert that turns out to be innocent. Common names create most of them. Fuzzy matching adds more, because it flags near spellings on purpose. Secondary identifiers are how you clear the noise without missing a true hit.

The logic is simple. If the name matches but the date of birth is 20 years apart, it is not your party. If the passport number matches too, it almost certainly is. You use the extra fields to raise or drop your confidence.

• A name match with no other agreement is weak. Treat it as a lead, not a finding.
• A name match plus date of birth is strong. Investigate closely.
• A name match plus a passport or registration number is close to certain.
• A name match that conflicts on date of birth or nationality can often be cleared.

This is why enriching your own customer records matters. If you hold a date of birth and an ID number for each customer, you can resolve most alerts in minutes. If all you hold is a name, every common name becomes a slow manual review. For the full workflow, see our guide on how to resolve a false positive in denied party screening.

Weak aliases and why identifiers matter more

Some list entries include weak aliases. These are low quality names, like a nickname or a common phrase. OFAC marks them because they produce many false hits. A weak alias on its own should never block a transaction.

Secondary identifiers are how you handle these. When a weak alias fires, you look for supporting data. If a date of birth or an ID number also matches, the alert deserves real review. If nothing else lines up, you can usually clear it. This keeps you compliant without freezing every order.

A practical matching workflow

Use a set order so every analyst works the same way. A consistent process is easier to audit and easier to train.

1. Confirm the name match. Note whether it is exact, fuzzy, or a weak alias.
2. Compare date of birth. A clear conflict often clears an individual match.
3. Compare nationality and place of birth. Agreement raises confidence.
4. Compare the strongest number you hold. Passport, national ID, registration number, or IMO.
5. Weigh the address last. It supports a decision but rarely settles one.
6. Record the fields you compared and the reason for your call.

Two rules keep this honest. Never confirm a match on the name alone. And never clear a strong hit just because one field is blank. Missing data is not the same as a mismatch. When key fields are absent, you may need to ask the customer for more detail before you decide.

When identifiers are missing

Real data is messy. A list entry may show only a name and a country. Your own record may lack a date of birth. This gap is normal, and it changes how you should act.

• List entry is thin. Do not clear the hit just because the list gives little. A sparse entry can still be a real target.
• Your record is thin. Collect more identifiers at onboarding so future screening is faster. Ask for date of birth and an ID number early.
• Both are thin. Escalate. A name-only match against a name-only entry needs human judgment and often a documentation request.

Good data collection up front prevents most of this pain. Building identifier capture into your intake process is covered in our note on sanctions screening in customer onboarding.

Tuning your screening system

Identifiers only help if your system uses them well. Two settings matter most. The first is your fuzzy matching threshold. Set it too tight and you miss real hits. Set it too loose and you drown in noise.

The second is how the system weights each field. A strong number match should carry more weight than an address. A date of birth conflict should lower the score. Calibrate these by risk, not with one global setting for every customer.

• Give passport, national ID, and registration numbers the highest weight.
• Treat date of birth as a strong confirmer and a strong disqualifier.
• Use nationality and address as support, not as proof.
• Review your thresholds on a schedule and after any big list change.

Whether you run this by hand or with software affects your capacity. The trade offs are set out in our comparison of automated vs manual denied party screening.

Recording your decisions

Every match decision needs a record. Regulators expect to see why you cleared or escalated a hit. The identifiers you compared are the core of that evidence.

Capture the list entry, the fields you checked, the result of each check, and who signed off. Keep it with the transaction. This is your audit trail, and it is what protects you if a decision is ever questioned. Weak screening records are a common finding in enforcement reviews.

Screening well is one part of a wider program. To see where it fits, start with our hub on denied party screening and the related guide on denied party screening and the OFAC SDN list.

Frequently Asked Questions

What is the difference between a primary and secondary identifier?

The primary identifier is the name, which triggers the alert. Secondary identifiers are the other fields, like date of birth or passport number, that confirm or clear the match. You should never confirm a hit on the name alone.

Which secondary identifier is the most reliable?

Unique numbers are the most reliable. A passport number, national ID, company registration number, or vessel IMO number is stable and hard to fake. Date of birth is also strong. Nationality and address are weaker on their own.

Can I clear a match if the identifiers do not agree?

Often, yes. A clear conflict, like a date of birth that differs by many years, can clear an individual match. But a blank field is not a conflict. If key identifiers are missing, escalate rather than clear.

Where do secondary identifiers come from?

They come from two places. Sanctions lists publish them for each listed party. You collect your own from customers and suppliers at onboarding. Screening compares the two, so richer data on both sides gives cleaner results.

Key Takeaways

Secondary identifiers turn a rough name match into a real decision. Collect date of birth and ID numbers at onboarding, weight strong numbers highest, and never confirm or clear on the name alone. Record the fields you checked so every call is defensible. When you need help building a screening process that holds up under review, contact us.