diff --git a/backend/app/config.py b/backend/app/config.py
index 2bee64f..f30daf5 100644
--- a/backend/app/config.py
+++ b/backend/app/config.py
@@ -59,8 +59,9 @@ class Settings(BaseSettings):
     # Session cookie
     SESSION_MAX_AGE: int = 60 * 60 * 8  # 8h
 
-    # Multipart upload limit (bytes) — Zoho exports rarely exceed 20 MB.
-    MAX_UPLOAD_BYTES: int = 20 * 1024 * 1024
+    # Multipart upload limit (bytes). Default 100 MB — full-year Zoho time-log
+    # exports can run 30-60 MB, and we want headroom. Override via env var.
+    MAX_UPLOAD_BYTES: int = 100 * 1024 * 1024
 
     @property
     def cookie_path(self) -> str: