Back to Basics: What is Identity Resolution?

TL;DR: Identity resolution connects data from multiple devices and channels into a single, anonymized customer view. It enables personalized, effective marketing even without third-party cookies.

Trying to reach your ideal audience today can be challenging. Customers demanding more personalization, privacy regulations becoming stricter, and the depreciation of the third party cookie means that there’s a lot for marketers and publishers to keep up with. Identity Resolution may be the key you’re looking for.

Identity resolution is the process of combining multiple identifiers — think transactions, profile information, and behaviors — across devices and touchpoints with data points collected along the way. This combination lets you build a cohesive, omnichannel view of your consumers so you can reach them when and where they are most likely to engage along the sales funnel.

“Identity” and “Identity Resolution” are terms thrown around a lot in digital advertising. But what do they mean, exactly? According to the IAB’s State of Data 2020, identity can be defined as the recognition and engagement of audiences across independent owned and paid market touchpoints. We can think of identity resolution as a way to connect these identifiers and behaviors of users, both known and unknown, to a single consumer profile.

Identity is a loaded topic, with lots to discuss and understand. Let’s go back to basics, breaking down Identity Resolution and what it means for you.

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What is Identity Resolution?

Let’s start with the two parts of this phrase: Identity and Resolution. Identity, in this case, means identifying a consumer, no matter where they are. Now, does this mean we can meet and greet each person and recognize their face? No, it does not.

At its most basic level, identity means the ability to identify a person online. When done successfully, advertisers can then reach the right people, interested in their products or services, at the right time with the right message.

Identity resolution refers to the anonymous profile of a consumer that is gathered across devices. For example, if you combine the data gathered from laptop browsers, cell phones, email subscriptions, CTVs, and offline purchases into one pool, you might get a very complete picture of a person. However, all of this data has been anonymized so that the marketer doesn’t know any identifying information – such as a name, email address, phone number, or street address. More generally, they may know the gender, age, location, and things that a person likes to read about online, purchase, etc.

Resolution, therefore, means the compiling of all of this information into one profile. Whereas the consumer may only conduct business activities in one browser, s/he may do personal shopping in another. Alternatively, this person’s mobile or tablet may have more data on what they like to do in their free time, shows they like to watch, or things they search for. Looking at just one of these devices separately from the other gives you only a piece of the puzzle. However, if you combine them together, the marketer has a fuller idea of who this consumer is on more than one screen or device.

So, identity resolution means connecting many different identifiers from multiple platforms and devices in real-time to enable people-based targeting, personalization, and measurement.

Different Types of Identity Resolutions

You can approach identity resolution in a number of different ways. Understanding the different types of identity solutions available to marketers and advertisers can help as you narrow down the best option for you and your business:

• Contextual identity: Rather than user data, contextual identity uses page content
• Cohorts: Cohorts consist of groups of anonymized profiles with common browsing histories or interests. Users can only be in a single cohort at a time, which can be very limiting for marketers. Cohorts can also present privacy issues — while the profiles are anonymous, it’s still possible to work backward and figure out a user’s identity.
• Authenticated or deterministic identity: Authenticated identities are based on facts, such as a user-provided phone number or email address. Authenticated identity takes the guesswork out of your marketing strategy, as you don’t have to wonder if a customer’s profile contains the correct data. Developing deterministic identities can be challenging, however, as they require consumers to provide verified information about themselves.
• Non-authenticated or probabilistic identity: Non-authenticated identities, also known as probabilistic identities, are anonymous consumer profiles created from data gathered across devices. This form of identity uses technology to assign a cluster of devices and browser signals to an ID that can be moved via established pipes into activation channels. These publicly available signals can include IP address, timestamp, or browser user agent. Probabilistic is data minimized so no email, home address or phone number are required. Marketers can expect more precise targeting across devices and domains, and the ability to frequency management, critical when courting new customers.

Deterministic Identity Resolution / Probabilistic Identity Resolution / Hybrid Approaches

There are three working approaches to identity resolution, and most modern platforms blend them.

Deterministic identity resolution matches users based on known, verified identifiers, typically a hashed email, login ID, phone number, or loyalty number. When a user logs into a publisher site with the same email they used at a retailer, those two events can be matched 1:1 with high confidence. Deterministic is the gold standard for accuracy, but its scale is limited to authenticated touchpoints. If a user never logs in, they may not be captured by a purely deterministic system.

Probabilistic identity resolution uses statistical models to infer that two events belong to the same person, based on signals like device type, IP address, location pattern, consented device and browser-level signals, and behavioral consistency. Probabilistic methods scale because they don’t require login, but accuracy depends entirely on the quality of the model and the richness of the signal. The trade-off is reach vs. precision.

Hybrid identity resolution combines both. Deterministic matches form a high-confidence spine; probabilistic methods extend that spine to unauthenticated traffic with controlled confidence thresholds. In practice, hybrid is what production systems actually run — pure deterministic approaches have limited scale, while pure probabilistic approaches can be harder to validate..

A practical way to evaluate any solution:

• Match rate: what percentage of impressions or events resolve to a person.
• Accuracy: how often the resolved identity is actually correct, and how that accuracy is validated (probabilistic models should publish confidence bands).
• Deterministic share: what proportion of matches come from verified signals vs. inference.
• Cross-device coverage: whether the system can connect web, mobile app, and CTV.
• Privacy posture: whether the underlying signals were collected with appropriate consent and supported by clear data lineage and auditability.

The right blend depends on your use case. A retailer with a loyalty program leans deterministic; a publisher monetizing logged-out readers needs probabilistic to scale; most marketers and platforms end up running hybrid.

Why Is Identity Resolution Important?

Identity resolution helps you understand your audience. It creates rules that sort data and eliminate duplicates, giving you an accurate picture of who your audience is. You can then use that information to market to potential customers and leads.

You also create a better customer experience with identity resolution. For example, a potential customer might visit a store’s website and browse around before creating an account. During this time, the potential customer is still relatively anonymous. While the site is collecting data on the products they’re viewing or adding to a cart, it doesn’t yet know who the customer is.

Then the customer decides to make a purchase. As they move through checkout, they sign up for an account with the website. With identity resolution, you can connect the dots between the browsing the customer did as an anonymous user and their browsing and purchases after creating an account. Using the combined information lets you give the customer more accurate product recommendations.

Identity resolution helps reduce the cost of customer acquisition, too. When you have a better understanding of people’s habits, you can streamline your marketing efforts and focus on the tactics that are most likely to work.

The 2026 State of Identity: Where We Actually Are

The big picture hasn’t changed: third-party signal loss is real, privacy regulation is tightening, and consumers expect personalization without surveillance. But the specifics in 2026 are worth a quick reset.

Cookie deprecation, finally. After multiple delays, the third-party cookie phase-out in Chrome is no longer hypothetical. Most marketers and publishers can no longer plan around an audience strategy that assumes cookies will be there next year. The teams still operating on cookie-based targeting are now actively losing reach quarter over quarter.

AI accelerating probabilistic methods. Machine learning has materially improved probabilistic identity resolution. Modern models can match accuracy that was probabilistic-only five years ago to something closer to deterministic confidence, and they do it at scale across CTV, mobile, and authenticated web. The trade-off curve between reach and accuracy is flatter than it used to be.

Privacy regulation expanding. GDPR and CCPA aren’t the whole picture anymore. Most US states now have their own consumer privacy law, and enforcement is moving from theoretical to active. The compliance bar is “demonstrate consent and lawful basis for every signal in the graph,” not “we have a cookie banner.”

Walled gardens leaning harder into first-party. Google, Meta, Amazon, and TikTok are increasingly building closed identity systems that only work inside their platforms. That’s good for their advertisers and challenging for everyone trying to maintain a consistent customer view across the open web and the walled gardens. Identity resolution that bridges both is more valuable than ever.

CTV is the new battleground. Connected TV is the fastest-growing addressable channel, and it’s almost entirely cookieless by design. Identity resolution that handles household graphs and IP-based matching at scale is now table stakes for CTV planning.

The takeaway: the strategic case for identity resolution is stronger in 2026 than it was when most marketers first encountered the term. The execution gap between leaders and laggards is widening.

Reasons why identity resolution is a critical part of digital marketing

1. Increasing Privacy Regulations

Consumers have expressed concerns about data privacy and some governments have responded to their concerns by passing legislation to protect consumer data and limit how marketers use that data. The California Consumer Privacy Act (CCPA) gives consumers several rights regarding their data and privacy.

• Consumers have the right to know how businesses will use and share the data it collects about consumers.
• Consumers have the right to delete their personal information, with some exceptions.
• They can opt-out of the sale of their information.
• Consumers can’t be discriminated against for exercising their rights under the CCPA.

In Europe, the General Data Protection Regulation (GDPR) also gives citizens of the European Union the right to know how their data is being used and the right to opt out of sharing data.

To comply with both the GDPR and CCPA, marketers need to take data protection and privacy seriously.

2. Depreciation of Third Party Cookies

In recent years, Google and Apple have both announced that they will begin to phase out the use of third-party cookies on their respective browsers. These cookies have allowed marketers to track users across devices and browsers, giving marketers an inside view of consumer activity. By tracking them, marketers can directly target consumers based on what they do online, such as the things they order or the stores they browse.

Without cookies, brands will have to change tactics for identifying users. Identity resolution and a first-party data strategy provide an excellent option.

3. Increased Consumer Demand for Personalization

Coupled with increased demands for privacy and control over their data, customers increasingly expect personalized marketing. Consumers want to see ads that are relevant to them that address their specific and unique concerns.

While it may seem as if they want the best of both worlds, identity resolution lets you give consumers the personalized experience they’ve come to expect without compromising their privacy.

Identity resolution lets you collect data in a transparent and compliant manner, providing the details you need to create an identity graph full of consumer data and behaviors. Using the data in the graph, you can sculpt a personalized experience that builds consumer loyalty and enhances trust

How Does Identity Resolution Work?

Identity Resolution relies on an Identity Resolution Platform to combine these disparate data sources into a cohesive view of the consumer across devices and platforms. This type of technology generally offers:

• Data collection in all environments, including cookieless.
• A persistent individual or household ID that delivers an enriched single view across platforms, devices and browsers for audience matching and measurement.
• An Identity graph that links all device identifiers, associated customer data and behaviors into a single view of the individual.
• Protection of consumer privacy by collecting all data in a compliant and transparent way.

With so many different identity solutions out there, it can be a challenge to narrow down which platforms and technology are right for your business. You can get started with our six questions for evaluating identity partners.

What Is an Identity Graph?

If identity resolution is the process, an identity graph is the result.

An identity graph (sometimes called an identity spine) is a structured database that maps every known signal, such as hashed emails, device IDs, cookie IDs, household connections, account numbers, and behavioral signatures, back to a single profile, representing a person, household, or device cluster. Every time a new signal comes in, the graph asks one question: does this belong to someone we already know, or is this a new node?

In practice, an identity graph is doing three jobs at once:

• Connecting: linking signals from different devices, browsers, and channels to the same underlying identity.
• Persisting: maintaining that link over time, even as cookies churn, devices change, and new signals appear.
• Decaying: recognizing when a signal is stale and shouldn’t be trusted anymore (a shared device that’s no longer shared, a recycled phone number).

The quality of an identity graph is measured on three axes. Scale: how many people it covers in a given market. Accuracy: how often the connections it makes are actually correct. Freshness: how quickly it incorporates new signals and retires dead ones.

Two important nuances:

• Identity graphs are not customer databases. A CRM holds your customers; an identity graph holds connections between identifiers. The two are complementary — the graph tells you that these five touchpoints likely belong to the same person; the CRM tells you what that person bought.
• There is no single, universal identity graph. Different platforms maintain different graphs with different inputs and strengths. A robust identity resolution strategy often combines an internal graph (your customer view) with one or more external graphs (broader cross-publisher reach).

If you’ve heard the term “identity spine” or “persistent ID” used somewhere, the underlying construct is the same.

Is Identity Resolution Privacy-Friendly?

Why yes, it is! So glad you asked. Lotame, in particular, collects customer data from any source, and then hashes it, or anonymizes that data before it is collected in our data management platform. This means that there is no Individual Identifying Information, such as names, email addresses, or street addresses stored in the platform. Data management platforms such as Lotame do process personal data, which includes cookie IDs, device identifiers and IP addresses.

The Importance of Privacy

Privacy matters to consumers, and no one wants to feel as if their every move is being watched and recorded.

Thanks to regulations like CCPA and GDPR, customers have some control over the data companies collect about them. A key tenet of both laws is the “right to be forgotten,” meaning consumers have the right to ask companies to erase any data connected to their identity.

Identity resolution honors a consumer’s right to be forgotten by keeping customer data separate. Rather than using third-party cookies, marketers remain in control of their own set of customer data. If necessary, a customer can request that the company delete their information.

How to Evaluate an Identity Resolution Solution

If you’re shopping for an identity resolution provider, the marketing pages tend to blur together. Here are the questions that actually separate the strong solutions from the marketing language.

Match rate and accuracy. Ask for both, and ask how each is measured. “95% match rate” means nothing without knowing whether the underlying matches were validated. Strong providers publish methodology.

Deterministic vs. probabilistic share. What percentage of matches come from verified, consented signals versus inference? Higher deterministic share is more trustworthy; higher probabilistic share usually means more reach. Neither is “right,” but the split should be transparent.

Cross-device and cross-channel coverage. Can the solution connect web, mobile app, CTV, and (where relevant) offline data? Identity resolution that only works on desktop web is a partial solution at best.

Privacy and consent posture. What signals does the underlying graph use? How were they collected? Does the provider comply with GDPR, CCPA, CPRA, and the major US state laws? Is there a clean audit trail from signal to match?

Cookieless durability. What happens to the solution’s match rate when third-party cookies disappear entirely? Some “identity resolution” products are still cookie-dependent under the hood. Ask. (See: cookieless identity solution case study.)

Integrations. Does the solution plug into your DSPs, SSPs, CDP, email tool, and walled gardens, or does it require a custom build for each destination? Integration coverage is where time-to-value lives.

Pricing model. Per-match, per-MAU, flat platform fee, or hybrid? Each model creates different incentives. Be wary of pricing that penalizes you for growth.

Reference customers. Ask for two or three in your industry, ideally one similar in scale. Talk to them about what worked and what didn’t.

Most identity resolution providers will gladly walk you through their answers. The ones that won’t are telling you something.

Identity Resolution Use Cases by Industry

The mechanics are consistent. The applications vary. Here are five examples of identity resolution in production.

Publishing. A national news publisher uses identity resolution to connect logged-in subscriber data, logged-out reader behavior, and authenticated newsletter activity into a single audience view. That unified view powers higher-CPM addressable advertising for sponsors and personalized content recommendations for readers, all without depending on third-party cookies that browsers no longer support.

Retail and e-commerce. A specialty retailer stitches in-store loyalty, website behavior, mobile app activity, and email engagement to recognize a returning customer across every channel. The customer service rep sees the full history; the email tool times sends around app activity; the paid media team suppresses recent buyers from prospecting campaigns. (Closely related: building a first party audience on top of resolved identity.)

Financial services. A bank resolves customer identity across web, mobile banking, branch interactions, and call-center notes to power next-best-product recommendations and fraud prevention simultaneously. The same identity layer that improves cross-sell also flags when a session pattern is inconsistent with the verified customer.

B2B. A SaaS company can help connect anonymous website behavior to likely accounts in the CRM (where supported by consented data and enrichment), then alerts the sales team when an active opportunity hits the pricing page. Identity resolution at the account level is what makes account-based marketing actually work in real time.

Streaming and CTV. A streaming platform connects household viewing behavior across devices and ad-supported tiers to deliver frequency caps that actually hold across screens, and to give advertisers addressable, deduplicated reach. Without identity resolution, the same household sees the same ad six times in three hours on three different devices.

The use cases differ; the underlying need is identical: one customer, one identity, every touchpoint connected, no matter how many devices or sessions sit between them.

How to Get Started with Identity Resolution

How will you future proof your business for a cookieless tomorrow? Lotame’s identity solution suite, Panorama preserves and extends addressability across the global open web and beyond. Here’s a brief look at how to use our Identity Resolution platform:

1. Onboard customer data: Your company may already have information on customers from a customer relationship management (CRM) platform or other sources. If so, you should upload it to your online environment.
2. Collect more data:Use Lotame’s Lightning Tag to connect all types of device identifiers into a single view of an individual.
3. Connect an identity graph: Lotame’s Panorama ID lets you use the Panorama Identity Graph to link all device identifiers, associated customer data and behaviors into a single view of the individual.
4. Activate: With an enriched single view of your customer across all platforforms, devices, and browsers, you can now create audiences extended across all linked devices for greater scale for audience targeting and more accurate measurement in activation channels.

Identity resolution is essential in order to meaningfully engage with consumers across all screens in a privacy compliant way. Learn more about our privacy-fist, opening accessible identity solution that creates a new common language for marketers and publishers to preserve connectivity in the digital ecosystem.

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