diff --git a/src/main/kotlin/uk/gov/justice/digital/hmpps/approvedpremisesapi/model/deliuscontext/CaseDetail.kt b/src/main/kotlin/uk/gov/justice/digital/hmpps/approvedpremisesapi/model/deliuscontext/CaseDetail.kt
index 086e896318..5ac69c3a4b 100644
--- a/src/main/kotlin/uk/gov/justice/digital/hmpps/approvedpremisesapi/model/deliuscontext/CaseDetail.kt
+++ b/src/main/kotlin/uk/gov/justice/digital/hmpps/approvedpremisesapi/model/deliuscontext/CaseDetail.kt
@@ -62,7 +62,7 @@ data class Profile(
 )
 
 data class Offence(
-  val id: Long,
+  val id: String,
   val description: String,
   val date: LocalDate?,
   val main: Boolean,
diff --git a/src/main/kotlin/uk/gov/justice/digital/hmpps/approvedpremisesapi/transformer/OffenceTransformer.kt b/src/main/kotlin/uk/gov/justice/digital/hmpps/approvedpremisesapi/transformer/OffenceTransformer.kt
index 9168c48e10..d9ba769599 100644
--- a/src/main/kotlin/uk/gov/justice/digital/hmpps/approvedpremisesapi/transformer/OffenceTransformer.kt
+++ b/src/main/kotlin/uk/gov/justice/digital/hmpps/approvedpremisesapi/transformer/OffenceTransformer.kt
@@ -22,7 +22,7 @@ class OffenceTransformer {
     ActiveOffence(
       deliusEventNumber = it.eventNumber,
       offenceDescription = it.description,
-      offenceId = it.id.toString(),
+      offenceId = it.id,
       convictionId = it.eventId,
       offenceDate = it.date,
     )
diff --git a/src/test/kotlin/uk/gov/justice/digital/hmpps/approvedpremisesapi/factory/CaseDetailFactory.kt b/src/test/kotlin/uk/gov/justice/digital/hmpps/approvedpremisesapi/factory/CaseDetailFactory.kt
index f0f79bd758..20339a8ea5 100644
--- a/src/test/kotlin/uk/gov/justice/digital/hmpps/approvedpremisesapi/factory/CaseDetailFactory.kt
+++ b/src/test/kotlin/uk/gov/justice/digital/hmpps/approvedpremisesapi/factory/CaseDetailFactory.kt
@@ -14,6 +14,7 @@ import uk.gov.justice.digital.hmpps.approvedpremisesapi.model.deliuscontext.Regi
 import uk.gov.justice.digital.hmpps.approvedpremisesapi.model.deliuscontext.Team
 import uk.gov.justice.digital.hmpps.approvedpremisesapi.util.randomLong
 import uk.gov.justice.digital.hmpps.approvedpremisesapi.util.randomStringLowerCase
+import uk.gov.justice.digital.hmpps.approvedpremisesapi.util.randomStringMultiCaseWithNumbers
 import uk.gov.justice.digital.hmpps.approvedpremisesapi.util.randomStringUpperCase
 import java.time.LocalDate
 import java.time.ZonedDateTime
@@ -49,14 +50,14 @@ class CaseDetailFactory : Factory<CaseDetail> {
 }
 
 class CaseDetailOffenceFactory : Factory<Offence> {
-  var id: Yielded<Long> = { randomLong() }
+  var id: Yielded<String> = { randomStringMultiCaseWithNumbers(9) }
   var description: Yielded<String> = { randomStringLowerCase(10) }
   var date: Yielded<LocalDate> = { LocalDate.now() }
   var main: Yielded<Boolean> = { false }
   var eventNumber: Yielded<String> = { randomStringLowerCase(10) }
   var eventId: Yielded<Long> = { randomLong() }
 
-  fun withId(id: Long) = apply {
+  fun withId(id: String) = apply {
     this.id = { id }
   }
 
diff --git a/src/test/kotlin/uk/gov/justice/digital/hmpps/approvedpremisesapi/integration/PersonOffencesTest.kt b/src/test/kotlin/uk/gov/justice/digital/hmpps/approvedpremisesapi/integration/PersonOffencesTest.kt
index 2caf620dcc..2aefb85df9 100644
--- a/src/test/kotlin/uk/gov/justice/digital/hmpps/approvedpremisesapi/integration/PersonOffencesTest.kt
+++ b/src/test/kotlin/uk/gov/justice/digital/hmpps/approvedpremisesapi/integration/PersonOffencesTest.kt
@@ -148,7 +148,7 @@ class PersonOffencesTest : InitialiseDatabasePerClassTestBase() {
           .withOffences(
             listOf(
               CaseDetailOffenceFactory()
-                .withId(1)
+                .withId("M1")
                 .withDescription("Test Offence 1")
                 .withDate(LocalDate.now().minusMonths(1))
                 .withEventNumber("123")
diff --git a/src/test/kotlin/uk/gov/justice/digital/hmpps/approvedpremisesapi/unit/transformer/OffenceTransformerTest.kt b/src/test/kotlin/uk/gov/justice/digital/hmpps/approvedpremisesapi/unit/transformer/OffenceTransformerTest.kt
index b452dba772..90d709df29 100644
--- a/src/test/kotlin/uk/gov/justice/digital/hmpps/approvedpremisesapi/unit/transformer/OffenceTransformerTest.kt
+++ b/src/test/kotlin/uk/gov/justice/digital/hmpps/approvedpremisesapi/unit/transformer/OffenceTransformerTest.kt
@@ -63,7 +63,7 @@ class OffenceTransformerTest {
       .withOffences(
         listOf(
           OffenceFactory()
-            .withOffenceId("1")
+            .withOffenceId("M1")
             .withMainCategoryDescription("A Description")
             .withSubCategoryDescription("A Description")
             .withOffenceDate(LocalDateTime.parse("2022-12-06T00:00:00"))
@@ -76,7 +76,7 @@ class OffenceTransformerTest {
       ActiveOffence(
         deliusEventNumber = "5",
         offenceDescription = "A Description",
-        offenceId = "1",
+        offenceId = "M1",
         convictionId = 12345,
         offenceDate = LocalDate.parse("2022-12-06"),
       ),
@@ -89,14 +89,14 @@ class OffenceTransformerTest {
       .withOffences(
         listOf(
           CaseDetailOffenceFactory()
-            .withId(10)
+            .withId("M10")
             .withDescription("A first offence")
             .withDate(LocalDate.parse("2024-11-01"))
             .withEventNumber("20")
             .withEventId(30)
             .produce(),
           CaseDetailOffenceFactory()
-            .withId(100)
+            .withId("A100")
             .withDescription("A second offence")
             .withDate(LocalDate.parse("2024-11-11"))
             .withEventNumber("200")
@@ -110,14 +110,14 @@ class OffenceTransformerTest {
       ActiveOffence(
         deliusEventNumber = "20",
         offenceDescription = "A first offence",
-        offenceId = "10",
+        offenceId = "M10",
         convictionId = 30,
         offenceDate = LocalDate.parse("2024-11-01"),
       ),
       ActiveOffence(
         deliusEventNumber = "200",
         offenceDescription = "A second offence",
-        offenceId = "100",
+        offenceId = "A100",
         convictionId = 300,
         offenceDate = LocalDate.parse("2024-11-11"),
       ),