diff --git a/app/admin_routes.py b/app/admin_routes.py
index a34031d..87b483c 100644
--- a/app/admin_routes.py
+++ b/app/admin_routes.py
@@ -1,5 +1,6 @@
 import re
 import secrets
+from datetime import datetime, timedelta
 
 import httpx
 from fastapi import APIRouter, Depends, HTTPException, Query
@@ -547,9 +548,24 @@ class BulkIn(BaseModel):
     value: float | int | str | None = None
 
 
+async def _fresh_sku(db):
+    """Canonical SKU = 14-digit product-added timestamp (YYYYMMDDHHMMSS) — the format SCANGOD's EPC/RFID
+    codec requires (packs SKU 14 digits × 10^9 + release_id onto the UHF chip). Bumps a second on
+    collision so a same-second batch stays unique against the sku PRIMARY KEY.
+    ponytail: check-then-insert; a truly concurrent same-second add on another connection could still hit
+    the PK and be ON CONFLICT DO NOTHING'd. Fine for counter/admin stock entry; add retry-on-conflict if
+    bulk-import concurrency grows."""
+    base = datetime.now()
+    for i in range(120):
+        sku = (base + timedelta(seconds=i)).strftime("%Y%m%d%H%M%S")
+        if not (await db.execute(text("SELECT 1 FROM inventory WHERE sku = :s"), {"s": sku})).first():
+            return sku
+    return (base + timedelta(seconds=120)).strftime("%Y%m%d%H%M%S")
+
+
 @router.post("/inventory/add")
 async def inv_add(body: InvItemIn, ident=Depends(require_token), db=Depends(get_db)):
-    sku = (body.sku or "").strip() or ("RG" + secrets.token_hex(4).upper())
+    sku = (body.sku or "").strip() or await _fresh_sku(db)
     title = body.title
     if body.release_id and not title:     # pull the cached title if intaking by release
         r = (await db.execute(text("SELECT title FROM disc_cache WHERE release_id=:r"),
@@ -629,7 +645,7 @@ async def inv_import(body: ImportIn, ident=Depends(require_token), db=Depends(ge
         if not rid:
             not_found.append(ln)
             continue
-        sku = "RG" + secrets.token_hex(4).upper()
+        sku = await _fresh_sku(db)
         await db.execute(text("""
             INSERT INTO inventory (sku, store_id, kind, release_id, title, price, qty, in_stock, condition,
                                    crate_id, status, created_at, updated_at)