diff --git a/scripts/build_ifta_quarterly_campaign.py b/scripts/build_ifta_quarterly_campaign.py
index c6506e3..51a1c08 100644
--- a/scripts/build_ifta_quarterly_campaign.py
+++ b/scripts/build_ifta_quarterly_campaign.py
@@ -249,7 +249,16 @@ def main() -> int:
     headline = headline_t.format(due=due_human)
 
     def attribs(dot, company, state):
-        lp = f"{LP_LINK}?code={coupon}" if coupon else LP_LINK
+        # lp_link MUST start its query with `?` so the body's `&utm_source=...`
+        # appends cleanly. A bare path here yields `/order/ifta-quarterly&utm...`
+        # (no `?`) which 404s. Carry the carrier's `?dot=` (and `?code=` when a
+        # coupon is on) exactly like the main builder's lp_link_with_coupon().
+        params = []
+        if dot:
+            params.append(f"dot={dot}")
+        if coupon:
+            params.append(f"code={coupon}")
+        lp = f"{LP_LINK}?" + "&".join(params) if params else LP_LINK
         a = {
             "dot_number": dot or "", "company": company or "", "state": state or "",
             "lp_link": lp,
diff --git a/scripts/build_trucking_campaigns.py b/scripts/build_trucking_campaigns.py
index 716a585..fd74906 100644
--- a/scripts/build_trucking_campaigns.py
+++ b/scripts/build_trucking_campaigns.py
@@ -232,17 +232,19 @@ def discounted_price_attribs(campaign_type: str, phy_state: str | None,
 
 def build_lp_link(campaign_type: str, phy_state: str | None) -> str:
     """Return the order landing-page URL for a (segment, state)."""
-    seg = DEFICIENCY_SEGMENTS.get(campaign_type)
-    slug = seg["lp_slug"] if seg else "dot-full-compliance"
-    if campaign_type == "state_weight_tax" and phy_state in _WEIGHT_TAX_LP:
-        slug = _WEIGHT_TAX_LP[phy_state]
-    if campaign_type == "state_emissions" and phy_state == "CA":
-        slug = "ca-mcp-carb"
-    return f"{SITE_DOMAIN}/order/{slug}"
+    return f"{SITE_DOMAIN}/order/{lp_slug_for(campaign_type, phy_state)}"
 
 
 def lp_slug_for(campaign_type: str, phy_state: str | None = None) -> str:
-    """The order-page slug (== the discountable service slug) for a segment."""
+    """The order-page slug (== the discountable service slug) for a segment.
+
+    Main (non-deficiency) campaigns route to their SPECIFIC service via
+    PRICE_SLUG_BY_CAMPAIGN (mcs150 -> mcs150-update $79, inactive ->
+    usdot-reactivation $149). Without this they fell through to the
+    `dot-full-compliance` ($399) catch-all — sending MCS-150/Inactive carriers
+    to a 5x-priced page they never asked for (severe conversion killer)."""
+    if campaign_type in PRICE_SLUG_BY_CAMPAIGN:
+        return PRICE_SLUG_BY_CAMPAIGN[campaign_type]
     seg = DEFICIENCY_SEGMENTS.get(campaign_type)
     slug = seg["lp_slug"] if seg else "dot-full-compliance"
     if campaign_type == "state_weight_tax" and phy_state in _WEIGHT_TAX_LP:
diff --git a/scripts/build_ucr_annual_campaign.py b/scripts/build_ucr_annual_campaign.py
index cb298fd..6e0b5b3 100644
--- a/scripts/build_ucr_annual_campaign.py
+++ b/scripts/build_ucr_annual_campaign.py
@@ -196,7 +196,16 @@ def main() -> int:
     urgency = urgency_t.format(year=year, due=due_human)
 
     def attribs(dot, company, state):
-        lp = f"{LP_LINK}?code={coupon}" if coupon else LP_LINK
+        # lp_link MUST start its query with `?` so the body's `&utm_source=...`
+        # appends cleanly. A bare path here yields `/order/ucr-registration&utm...`
+        # (no `?`) which 404s. Carry the carrier's `?dot=` (and `?code=` when a
+        # coupon is on) exactly like the main builder's lp_link_with_coupon().
+        params = []
+        if dot:
+            params.append(f"dot={dot}")
+        if coupon:
+            params.append(f"code={coupon}")
+        lp = f"{LP_LINK}?" + "&".join(params) if params else LP_LINK
         a = {
             "dot_number": dot or "", "company": company or "", "state": state or "",
             "lp_link": lp,