diff --git a/server/accounting/qb-receivables-lines.js b/server/accounting/qb-receivables-lines.js
index f51f9c161..c9e2fd1dd 100644
--- a/server/accounting/qb-receivables-lines.js
+++ b/server/accounting/qb-receivables-lines.js
@@ -38,7 +38,9 @@ exports.default = function ({
 
       if (
         (jobline.prt_dsmk_p && jobline.prt_dsmk_p !== 0) ||
-        jobline.prt_dsmk_m !== 0
+        ((jobline.db_ref === "900511" || jobline.db_ref === "900510") &&
+          jobline.prt_dsmk_m &&
+          jobline.prt_dsmk_m !== 0)
       ) {
         // console.log("Have a part discount", jobline);
         DineroAmount = DineroAmount.add(
diff --git a/server/cdk/cdk-calculate-allocations.js b/server/cdk/cdk-calculate-allocations.js
index 65f22ce27..b4709bd67 100644
--- a/server/cdk/cdk-calculate-allocations.js
+++ b/server/cdk/cdk-calculate-allocations.js
@@ -70,7 +70,12 @@ exports.default = async function (socket, jobid) {
           amount: Math.round(val.act_price * 100),
         }).multiply(val.part_qty || 1);
 
-        if ((val.prt_dsmk_p && val.prt_dsmk_p !== 0) || val.prt_dsmk_m !== 0) {
+        if (
+          (val.prt_dsmk_p && val.prt_dsmk_p !== 0) ||
+          ((val.db_ref === "900511" || val.db_ref === "900510") &&
+            val.prt_dsmk_m &&
+            val.prt_dsmk_m !== 0)
+        ) {
           // console.log("Have a part discount", val);
           DineroAmount = DineroAmount.add(
             val.prt_dsmk_m && val.prt_dsmk_m !== 0
diff --git a/server/job/job-totals.js b/server/job/job-totals.js
index 4cae85d74..74fabff78 100644
--- a/server/job/job-totals.js
+++ b/server/job/job-totals.js
@@ -270,7 +270,10 @@ function CalculatePartsTotals(jobLines) {
                   })
                     .multiply(value.part_qty || 0)
                     .add(
-                      value.prt_dsmk_m && value.prt_dsmk_m !== 0
+                      (value.db_ref === "900511" ||
+                        value.db_ref === "900510") &&
+                        value.prt_dsmk_m &&
+                        value.prt_dsmk_m !== 0
                         ? Dinero({ amount: Math.round(value.prt_dsmk_m * 100) })
                         : Dinero({
                             amount: Math.round(value.act_price * 100),
@@ -295,7 +298,9 @@ function CalculatePartsTotals(jobLines) {
               parts: {
                 ...acc.parts,
                 prt_dsmk_total: acc.parts.prt_dsmk_total.add(
-                  value.prt_dsmk_m && value.prt_dsmk_m !== 0
+                  (value.db_ref === "900511" || value.db_ref === "900510") &&
+                    value.prt_dsmk_m &&
+                    value.prt_dsmk_m !== 0
                     ? Dinero({ amount: Math.round(value.prt_dsmk_m * 100) })
                     : Dinero({
                         amount: Math.round(value.act_price * 100),
@@ -339,7 +344,9 @@ function CalculatePartsTotals(jobLines) {
                     }).multiply(value.part_qty || 0)
                   )
                   .add(
-                    value.prt_dsmk_m && value.prt_dsmk_m !== 0
+                    (value.db_ref === "900511" || value.db_ref === "900510") &&
+                      value.prt_dsmk_m &&
+                      value.prt_dsmk_m !== 0
                       ? Dinero({ amount: Math.round(value.prt_dsmk_m * 100) })
                       : Dinero({
                           amount: Math.round(value.act_price * 100),