diff --git a/client/src/graphql/jobs.queries.js b/client/src/graphql/jobs.queries.js
index 84d3341c4..a389c8f76 100644
--- a/client/src/graphql/jobs.queries.js
+++ b/client/src/graphql/jobs.queries.js
@@ -535,6 +535,7 @@ export const GET_JOB_BY_PK = gql`
         unq_seq
         line_ind
         line_desc
+        line_ref
         part_type
         oem_partno
         db_price
diff --git a/server/graphql-client/queries.js b/server/graphql-client/queries.js
index 61294e008..d5674fd5c 100644
--- a/server/graphql-client/queries.js
+++ b/server/graphql-client/queries.js
@@ -797,6 +797,7 @@ exports.GET_JOB_BY_PK = ` query GET_JOB_BY_PK($id: uuid!) {
         line_ind
         line_desc
         part_type
+        line_ref
         oem_partno
         db_price
         act_price
diff --git a/server/job/job-totals.js b/server/job/job-totals.js
index 74fabff78..7262a332a 100644
--- a/server/job/job-totals.js
+++ b/server/job/job-totals.js
@@ -486,7 +486,9 @@ function CalculateTaxesTotals(job, otherTotals) {
           Dinero({ amount: Math.round((val.act_price || 0) * 100) })
             .multiply(val.part_qty || 0)
             .add(
-              val.prt_dsmk_m && val.prt_dsmk_m !== 0
+              val.prt_dsmk_m &&
+                val.prt_dsmk_m !== 0 &&
+                DiscountNotAlreadyCounted(val, job.joblines)
                 ? Dinero({ amount: Math.round(val.prt_dsmk_m * 100) })
                 : Dinero({
                     amount: Math.round(val.act_price * 100),
@@ -566,3 +568,9 @@ function CalculateTaxesTotals(job, otherTotals) {
 }
 
 exports.default = Totals;
+
+function DiscountNotAlreadyCounted(jobline, joblines) {
+  if (jobline.db_ref !== "900510") return true;
+  const ParentLine = joblines.find((j) => j.unq_seq === jobline.line_ref);
+  return ParentLine && !(ParentLine.prt_dsmk_m && ParentLine.prt_dsmk_m !== 0);
+}