diff --git a/src/store/index.js b/src/store/index.js
index e0d32e74..a131748c 100644
--- a/src/store/index.js
+++ b/src/store/index.js
@@ -118,7 +118,8 @@ export const getDefaultState = () => ({
             cvrgEndorsementCode: null,
             status: null,
             policyData: null,
-            policyLookupErrorCode: 0
+            policyLookupErrorCode: 0,
+            memberNumber: null
         },
         customer: {
             address: {
@@ -587,7 +588,7 @@ export const useMainStore = defineStore({
                 };
                 // Clients (i.e. USAA) may sometimes use member number, which is just policy number by a different name
                 if (this.issConfig.useMemberNumber) {
-                    payload.memberNumber = policy.policyNumber;
+                    payload.memberNumber = policy.memberNumber ?? policy.policyNumber;
                 }
                 const response = await globalMethods.callHttpClient({
                     method: endpoints.CoveragePolicyInfo.method,
@@ -617,6 +618,13 @@ export const useMainStore = defineStore({
 
                     // populate additional fields
                     order.policy.policyData = responsePolicy.policyData;
+                    if (this.issConfig.useMemberNumber) {
+                        if (!order.policy.memberNumber) {
+                            // We only do this once, otherwise we would overwrite the member number with the policy number on subsequent lookups.
+                            order.policy.memberNumber = order.policy.policyNumber;
+                        }
+                        order.policy.policyNumber = responsePolicy.policyNumber;
+                    }
 
                     // populate vehicles
                     order.policy.vehicles = responsePolicy.vehicles ?? [];
@@ -716,7 +724,7 @@ export const useMainStore = defineStore({
                 };
                 // Clients (i.e. USAA) may sometimes use member number, which is just policy number by a different name
                 if (this.issConfig.useMemberNumber) {
-                    payload.memberNumber = this.order.policy.policyNumber;
+                    payload.memberNumber = this.order.policy.memberNumber ?? this.order.policy.policyNumber;
                 }
                 await updateClientSpecificFieldsForClaimRegistration(payload, this.order);
                 const response = await globalMethods.callHttpClient({
@@ -777,7 +785,7 @@ export const useMainStore = defineStore({
             };
             // Clients (i.e. USAA) may sometimes use member number, which is just policy number by a different name
             if (this.issConfig.useMemberNumber) {
-                payload.memberNumber = this.order.policy.policyNumber;
+                payload.memberNumber = this.order.policy.memberNumber ?? this.order.policy.policyNumber;
             }
 
             try {
@@ -1827,6 +1835,7 @@ export const useMainStore = defineStore({
                 order.policy.isDamageGlassOnly = data?.policy?.isDamageGlassOnly;
                 order.policy.policyNumber = data?.policy?.policyNumber;
                 order.policy.policyZipCode = data?.policy?.policyZipCode;
+                order.policy.memberNumber = data?.policy?.memberNumber;
 
                 order.referralNumber = data?.referralNumber;
                 order.referralDate = data?.referralDate;
@@ -2207,6 +2216,7 @@ export const useMainStore = defineStore({
             this.order.policy.policyLookupErrorCode = 0;
             this.order.policy.deductible.repair = null;
             this.order.policy.deductible.replace = null;
+            this.order.policy.memberNumber = null;
         },
 
         resetPayment() {