diff --git a/server/providers/OpenAI.js b/server/providers/OpenAI.js
index 19b0f52a3..570c3e919 100644
--- a/server/providers/OpenAI.js
+++ b/server/providers/OpenAI.js
@@ -240,12 +240,25 @@ class OpenAI {
     return resultBooks.map((book) => {
       const seriesName = this.normalizeSeriesName(book.seriesName)
       const sequence = this.normalizeSequence(book.sequence)
+      const reason = typeof book.reason === 'string' ? book.reason.trim() : ''
 
       if (seriesName && !sequence) {
-        throw new Error(`OpenAI returned a series without a valid sequence for "${book.id}"`)
+        Logger.warn(`[OpenAI] Series "${seriesName}" for book "${book.id}" did not include a valid sequence - skipping assignment`)
+        return {
+          id: book.id,
+          seriesName: null,
+          sequence: null,
+          reason: reason ? `${reason} (skipped due to missing or invalid sequence)` : 'Skipped due to missing or invalid sequence'
+        }
       }
       if (!seriesName && sequence) {
-        throw new Error(`OpenAI returned a sequence without a series for "${book.id}"`)
+        Logger.warn(`[OpenAI] Sequence "${sequence}" for book "${book.id}" did not include a series name - skipping assignment`)
+        return {
+          id: book.id,
+          seriesName: null,
+          sequence: null,
+          reason: reason ? `${reason} (skipped due to missing series name)` : 'Skipped due to missing series name'
+        }
       }
 
       if (seriesName && sequence) {
@@ -259,7 +272,7 @@ class OpenAI {
             id: book.id,
             seriesName: null,
             sequence: null,
-            reason: typeof book.reason === 'string' ? `${book.reason.trim()} (skipped due to duplicate inferred sequence)` : 'Skipped due to duplicate inferred sequence'
+            reason: reason ? `${reason} (skipped due to duplicate inferred sequence)` : 'Skipped due to duplicate inferred sequence'
           }
         }
         seriesSequences.get(key).add(sequence)
@@ -269,7 +282,7 @@ class OpenAI {
         id: book.id,
         seriesName,
         sequence,
-        reason: typeof book.reason === 'string' ? book.reason.trim() : ''
+        reason
       }
     })
   }
diff --git a/test/server/providers/OpenAI.test.js b/test/server/providers/OpenAI.test.js
index fee086e4d..30ead5305 100644
--- a/test/server/providers/OpenAI.test.js
+++ b/test/server/providers/OpenAI.test.js
@@ -67,17 +67,34 @@ describe('OpenAI', () => {
       expect(result[1].sequence).to.equal('1.5')
     })
 
-    it('rejects a series assignment without sequence', () => {
-      expect(() =>
-        openAI.validateSeriesDetectionPayload(
-          {
-            books: [
-              { id: 'a', seriesName: 'Series Name', sequence: null }
-            ]
-          },
-          [{ id: 'a' }]
-        )
-      ).to.throw('without a valid sequence')
+    it('skips a series assignment without sequence', () => {
+      const result = openAI.validateSeriesDetectionPayload(
+        {
+          books: [
+            { id: 'a', seriesName: 'Series Name', sequence: null, reason: 'folder match' }
+          ]
+        },
+        [{ id: 'a' }]
+      )
+
+      expect(result[0].seriesName).to.equal(null)
+      expect(result[0].sequence).to.equal(null)
+      expect(result[0].reason).to.contain('skipped due to missing or invalid sequence')
+    })
+
+    it('skips a sequence without series name', () => {
+      const result = openAI.validateSeriesDetectionPayload(
+        {
+          books: [
+            { id: 'a', seriesName: null, sequence: '2', reason: 'sequence found' }
+          ]
+        },
+        [{ id: 'a' }]
+      )
+
+      expect(result[0].seriesName).to.equal(null)
+      expect(result[0].sequence).to.equal(null)
+      expect(result[0].reason).to.contain('skipped due to missing series name')
     })
   })
 })