diff --git a/build.gradle b/build.gradle
index 5257860..2ffe9c4 100644
--- a/build.gradle
+++ b/build.gradle
@@ -12,7 +12,7 @@ buildscript {
     }
 }
 
-version "4.1.0"
+version "4.2.0-SNAPSHOT"
 group "org.grails.plugins"
 
 apply plugin:"eclipse"
diff --git a/grails-app/conf/application.yml b/grails-app/conf/application.yml
index 0cbc242..096940f 100644
--- a/grails-app/conf/application.yml
+++ b/grails-app/conf/application.yml
@@ -8,3 +8,6 @@ info:
         name: '@info.app.name@'
         version: '@info.app.version@'
         grailsVersion: '@info.app.grailsVersion@'
+
+fathom:
+    site-id: 'TZHQTOVF'
\ No newline at end of file
diff --git a/grails-app/services/au/org/ala/bootstrap3/TagLinkService.groovy b/grails-app/services/au/org/ala/bootstrap3/TagLinkService.groovy
index 6e2aedd..9b400d9 100644
--- a/grails-app/services/au/org/ala/bootstrap3/TagLinkService.groovy
+++ b/grails-app/services/au/org/ala/bootstrap3/TagLinkService.groovy
@@ -45,6 +45,8 @@ class TagLinkService {
     String headerAndFooterVersion = "2"
     @Value('${security.oidc.enabled:false}')
     Boolean isOidc = false
+    @Value('${fathom.site-id}')
+    String fathomSiteId
 
     @Autowired
     LinkGenerator grailsLinkGenerator
@@ -315,6 +317,7 @@ class TagLinkService {
         content = content.replace('::myProfileURL::', encodeOutput(buildMyProfileLink(request, attrs)))
         content = content.replace('::editAccountLink::', encodeOutput(buildEditAccountLink(request, attrs)))
         content = content.replace('::loginStatus::', signedInOutClass)
+        content = content.replace('::fathomID::', attrs?.fathomSiteId ?: fathomSiteId)
 
         return content
     }
diff --git a/src/test/groovy/au/org/ala/bootstrap3/HeaderFooterTagLibSpec.groovy b/src/test/groovy/au/org/ala/bootstrap3/HeaderFooterTagLibSpec.groovy
index c1fa9f5..1e3301e 100644
--- a/src/test/groovy/au/org/ala/bootstrap3/HeaderFooterTagLibSpec.groovy
+++ b/src/test/groovy/au/org/ala/bootstrap3/HeaderFooterTagLibSpec.groovy
@@ -94,6 +94,18 @@ class HeaderFooterTagLibSpec extends Specification implements TagLibUnitTest<Hea
         result.startsWith(expected) || result.startsWith(' ' + expected)
     }
 
+    void "test fathomId substitution" () {
+        given:
+        tagLib.tagLinkService.hfCache['footer'].content = "::fathomID::"
+        tagLib.tagLinkService.hfCache['footer'].timestamp = new Date().time
+
+        when:
+        def result = tagLib.footer()
+
+        then:
+        result == grailsApplication.config.getProperty('fathom.site-id')
+    }
+
     void "test head"() {
         given:
         def expected = '<!-- head -->'