diff --git a/src/constants/endpoints.js b/src/constants/endpoints.js
index cfcd501c..c55410da 100644
--- a/src/constants/endpoints.js
+++ b/src/constants/endpoints.js
@@ -139,7 +139,7 @@ const endpoints = Object.freeze({
     },
     TaxOrderItems: {
         url: `${PRICE_BASE_URL}/taxed-order-items`,
-        method: 'GET'
+        method: 'POST'
     },
     LogExperimentExposureIfAssigned: {
         url: `${EXPERIMENTS_BASE_URL}/log-exposure`,
diff --git a/src/store/index.js b/src/store/index.js
index 731efee1..1d6e44b7 100644
--- a/src/store/index.js
+++ b/src/store/index.js
@@ -2365,38 +2365,27 @@ export const useMainStore = defineStore({
             const serviceLocationCity = serviceLocation.city;
             const serviceLocationState = serviceLocation.state;
             const serviceLocationZipCode = serviceLocation.zipCode;
-
-            const lineItemsQueryString = getTaxLineItemQueryString(pricedLineItems, 'lineItems');
-
-            let queryString = '';
-            if (appointmentType === AppointmentTypeStrings.MOBILE
-                || appointmentType === AppointmentTypeStrings.MOBILE_NOT_ITAC_AND_NOT_NOCOMP) {
-                queryString =
-                `ParentAccountNumber=${this.order.parentAccountNumber}`
-                + `&BillToAccountNumber=${this.billToAccountNumber}`
-                + `&ProviderNumber=${this.providerNumber}`
-                + `&AppointmentType=${appointmentType}`
-                + `&ServiceLocation.City=${serviceLocationCity}`
-                + `&ServiceLocation.State=${serviceLocationState}`
-                + `&ServiceLocation.ZipCode=${serviceLocationZipCode}`
-                + `${lineItemsQueryString}`;
-            } else {
-                queryString =
-                `ParentAccountNumber=${this.order.parentAccountNumber}`
-                + `&BillToAccountNumber=${this.billToAccountNumber}`
-                + `&ProviderNumber=${this.providerNumber}`
-                + `&AppointmentType=${appointmentType}`
-                + `${lineItemsQueryString}`;
-            }
-
             const lineItemServerData = this.order.lineItems.serverData;
-            if (lineItemServerData) {
-                queryString += `&ServerData=${encodeURIComponent(lineItemServerData)}`;
-            }
 
+            const isMobileApt = appointmentType === AppointmentTypeStrings.MOBILE
+                || appointmentType === AppointmentTypeStrings.MOBILE_NOT_ITAC_AND_NOT_NOCOMP;
+            
             const retPricedLineItems = await globalMethods.callHttpClient({
                 method: endpoints.TaxOrderItems.method,
-                endpoint: `${endpoints.TaxOrderItems.url}?${queryString}`
+                endpoint: endpoints.TaxOrderItems.url,
+                payload: {
+                ParentAccountNumber: this.order.parentAccountNumber,
+                BillToAccountNumber: this.billToAccountNumber,
+                ProviderNumber: this.providerNumber,
+                AppointmentType: appointmentType,
+                PricedLineItems: getLineItemsFlattened(pricedLineItems),
+                ServiceLocation: {
+                    City: isMobileApt ? serviceLocationCity : null,
+                    State: isMobileApt ? serviceLocationState : null,
+                    ZipCode: isMobileApt ? serviceLocationZipCode : null,
+                },
+                ServerData: lineItemServerData ? lineItemServerData : "",
+            },
             }).then((response) => {
                 this.order.lineItems.serverData = response.data.serverData;
                 return addTaxesToPricedLineItems(pricedLineItems, response.data.taxedLineItems);