diff --git a/internal/incoming/web/api_files.go b/internal/incoming/web/api_files.go
index a93620e..13a4fdd 100644
--- a/internal/incoming/web/api_files.go
+++ b/internal/incoming/web/api_files.go
@@ -23,6 +23,7 @@ import (
 	"fmt"
 	"io"
 	"net/http"
+	"strings"
 
 	"github.com/moov-io/ach"
 	"github.com/moov-io/achgateway/internal/incoming"
@@ -164,6 +165,9 @@ func (c *FilesController) CancelFileHandler(w http.ResponseWriter, r *http.Reque
 }
 
 func (c *FilesController) cancelFile(shardKey, fileID string) error {
+	// Remove .ach suffix if the request added it
+	fileID = strings.TrimSuffix(fileID, ".ach")
+
 	bs, err := compliance.Protect(c.cfg.Transform, models.Event{
 		Event: incoming.CancelACHFile{
 			FileID:   fileID,
diff --git a/internal/incoming/web/api_files_test.go b/internal/incoming/web/api_files_test.go
index 9b7c4a9..606c75a 100644
--- a/internal/incoming/web/api_files_test.go
+++ b/internal/incoming/web/api_files_test.go
@@ -89,7 +89,7 @@ func TestCancelFileHandler(t *testing.T) {
 	controller.AppendRoutes(r)
 
 	// Cancel our file
-	req := httptest.NewRequest("DELETE", "/shards/s2/files/f2", nil)
+	req := httptest.NewRequest("DELETE", "/shards/s2/files/f2.ach", nil)
 
 	w := httptest.NewRecorder()
 	r.ServeHTTP(w, req)
@@ -102,6 +102,6 @@ func TestCancelFileHandler(t *testing.T) {
 	var file incoming.CancelACHFile
 	require.NoError(t, models.ReadEvent(msg.Body, &file))
 
-	require.Equal(t, "f2", file.FileID)
+	require.Equal(t, "f2", file.FileID) // make sure .ach suffix is trimmed
 	require.Equal(t, "s2", file.ShardKey)
 }