diff --git a/spec_artifacts_process/schemas/plan-frontmatter.schema.json b/spec_artifacts_process/schemas/plan-frontmatter.schema.json
index 7d8ec86..2c7a7af 100644
--- a/spec_artifacts_process/schemas/plan-frontmatter.schema.json
+++ b/spec_artifacts_process/schemas/plan-frontmatter.schema.json
@@ -10,7 +10,7 @@
   "properties": {
     "id": {
       "type": "string",
-      "pattern": "^[A-Z]{2,4}-[0-9]+$"
+      "pattern": "^[A-Za-z]{2,4}-[0-9]+$"
     },
     "title": {
       "type": "string",
diff --git a/spec_artifacts_process/schemas/task-frontmatter.schema.json b/spec_artifacts_process/schemas/task-frontmatter.schema.json
index 7042cce..c1034e9 100644
--- a/spec_artifacts_process/schemas/task-frontmatter.schema.json
+++ b/spec_artifacts_process/schemas/task-frontmatter.schema.json
@@ -10,7 +10,7 @@
   "properties": {
     "id": {
       "type": "string",
-      "pattern": "^[A-Z]{2,4}-[0-9]+$"
+      "pattern": "^[A-Za-z]{2,4}-[0-9]+$"
     },
     "title": {
       "type": "string",