diff --git a/Core/UserAgentManager.swift b/Core/UserAgentManager.swift
index 7e3571c0b0..5f57b7807a 100644
--- a/Core/UserAgentManager.swift
+++ b/Core/UserAgentManager.swift
@@ -113,7 +113,7 @@ struct UserAgent {
         static let ddgFixedUserAgentConfigKey = "ddgFixedUserAgent"
 
         static let uaVersionsKey = "versions"
-        static let uaStateKey = "state" // todo: do we need it?
+        static let uaStateKey = "state"
         // swiftlint:enable line_length
     }
     
@@ -128,14 +128,15 @@ struct UserAgent {
     private let versionComponent: String
     private let safariComponent: String
     private let applicationComponent = "DuckDuckGo/\(AppVersion.shared.majorVersionNumber)"
-    private let statistics: StatisticsUserDefaults = StatisticsUserDefaults()
+    private let statistics: StatisticsStore
     private let isTesting: Bool = ProcessInfo().arguments.contains("testing")
     
-    init(defaultAgent: String = Constants.fallbackDefaultAgent) {
+    init(defaultAgent: String = Constants.fallbackDefaultAgent, statistics: StatisticsStore = StatisticsUserDefaults()) {
         versionComponent = UserAgent.createVersionComponent(fromAgent: defaultAgent)
         baseAgent = UserAgent.createBaseAgent(fromAgent: defaultAgent, versionComponent: versionComponent)
         baseDesktopAgent = UserAgent.createBaseDesktopAgent(fromAgent: defaultAgent, versionComponent: versionComponent)
         safariComponent = UserAgent.createSafariComponent(fromAgent: baseAgent)
+        self.statistics = statistics
     }
     
     private func omitApplicationSites(forConfig config: PrivacyConfiguration) -> [String] {
@@ -168,16 +169,16 @@ struct UserAgent {
 
     private func closestUserAgentVersions(forConfig config: PrivacyConfiguration) -> [String] {
         let uaSettings = config.settings(for: .customUserAgent)
-        let closestUserAgentObjs = uaSettings[Constants.closestUserAgentConfigKey] as? [[String: String]] ?? []
-        return [""]
-//        return  closestUserAgentObjs.map { $0[Constants.uaOmitDomainConfigKey] ?? "" }
+        let closestUserAgent = uaSettings[Constants.closestUserAgentConfigKey] as? [String: Any] ?? [:]
+        let versions = closestUserAgent[Constants.uaVersionsKey] as? [String] ?? []
+        return versions
     }
 
     private func ddgFixedUserAgentVersions(forConfig config: PrivacyConfiguration) -> [String] {
         let uaSettings = config.settings(for: .customUserAgent)
-        let closestUserAgentObjs = uaSettings[Constants.closestUserAgentConfigKey] as? [[String: String]] ?? []
-        return [""]
-//        return  closestUserAgentObjs.map { $0[Constants.uaOmitDomainConfigKey] ?? "" }
+        let fixedUserAgent = uaSettings[Constants.ddgFixedUserAgentConfigKey] as? [String: Any] ?? [:]
+        let versions = fixedUserAgent[Constants.uaVersionsKey] as? [String] ?? []
+        return versions
     }
 
     public func agent(forUrl url: URL?,
@@ -196,6 +197,14 @@ struct UserAgent {
             url?.isPart(ofDomain: domain) ?? false
         }) { return ddgFixedLogic(forUrl: url, isDesktop: isDesktop, privacyConfig: privacyConfig) }
 
+        if closestUserAgentVersions(forConfig: privacyConfig).contains(statistics.atb ?? "") {
+            return closestLogic(forUrl: url, isDesktop: isDesktop, privacyConfig: privacyConfig)
+        }
+
+        if ddgFixedUserAgentVersions(forConfig: privacyConfig).contains(statistics.atb ?? "") {
+            return ddgFixedLogic(forUrl: url, isDesktop: isDesktop, privacyConfig: privacyConfig)
+        }
+
         switch defaultPolicy(forConfig: privacyConfig) {
         case .ddg: return oldLogic(forUrl: url, isDesktop: isDesktop, privacyConfig: privacyConfig)
         case .ddgFixed: return ddgFixedLogic(forUrl: url, isDesktop: isDesktop, privacyConfig: privacyConfig)
diff --git a/DuckDuckGoTests/UserAgentTests.swift b/DuckDuckGoTests/UserAgentTests.swift
index be7bb014fd..0b1f73475f 100644
--- a/DuckDuckGoTests/UserAgentTests.swift
+++ b/DuckDuckGoTests/UserAgentTests.swift
@@ -22,7 +22,8 @@ import XCTest
 import BrowserServicesKit
 @testable import Core
 
-class UserAgentTests: XCTestCase {
+// swiftlint:disable file_length type_body_length
+final class UserAgentTests: XCTestCase {
     
     private struct DefaultAgent {
         static let mobile = "Mozilla/5.0 (iPhone; CPU iPhone OS 12_4 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Mobile/15E148"
@@ -362,4 +363,61 @@ class UserAgentTests: XCTestCase {
         XCTAssertEqual(ExpectedAgent.mobileFixed, testee.agent(forUrl: Constants.ddgFixedUrl, isDesktop: false, privacyConfig: config))
     }
 
+    let configWithVersions = """
+    {
+        "features": {
+            "customUserAgent": {
+                "state": "enabled",
+                "settings": {
+                    "defaultPolicy": "ddg",
+                    "omitApplicationSites": [
+                        {
+                            "domain": "cvs.com",
+                            "reason": "Site reports browser not supported"
+                        }
+                    ],
+                    "closestUserAgent": {
+                        "versions": ["v350-1", "v360-1"]
+                    },
+                    "ddgFixedUserAgent": {
+                        "versions": ["v351-1", "v361-1"]
+                    }
+                },
+                "exceptions": []
+            }
+        },
+        "unprotectedTemporary": []
+    }
+    """.data(using: .utf8)!
+
+    func testWhenAtbDoesNotMatchVersionFromConfigThenDefaultUAIsUsed() {
+        let statisticsStore = MockStatisticsStore()
+        statisticsStore.atb = "v300-1"
+        let testee = UserAgent(defaultAgent: DefaultAgent.mobile, statistics: statisticsStore)
+        let config = makePrivacyConfig(from: configWithVersions)
+        XCTAssertEqual(ExpectedAgent.mobile, testee.agent(forUrl: Constants.url, isDesktop: false, privacyConfig: config))
+    }
+
+    func testWhenAtbMatchesVersionInClosestUserAgentThenClosestUAIsUsed() {
+        let statisticsStore = MockStatisticsStore()
+        statisticsStore.atb = "v360-1"
+        let testee = UserAgent(defaultAgent: DefaultAgent.mobile, statistics: statisticsStore)
+        let config = makePrivacyConfig(from: configWithVersions)
+        XCTAssertEqual(ExpectedAgent.mobileClosest, testee.agent(forUrl: Constants.url, isDesktop: false, privacyConfig: config))
+    }
+
+    func testWhenAtbMatchesVersionInDDGFixedUserAgentThenDDGFixedUAIsUsed() {
+        let statisticsStore = MockStatisticsStore()
+        statisticsStore.atb = "v361-1"
+        let testee = UserAgent(defaultAgent: DefaultAgent.mobile, statistics: statisticsStore)
+        let config = makePrivacyConfig(from: configWithVersions)
+        XCTAssertEqual(ExpectedAgent.mobileFixed, testee.agent(forUrl: Constants.url, isDesktop: false, privacyConfig: config))
+    }
+
 }
+
+
+
+                               
+
+