diff --git a/src/common/project-helper.js b/src/common/project-helper.js
index a2d5cec..0be5e9d 100644
--- a/src/common/project-helper.js
+++ b/src/common/project-helper.js
@@ -9,16 +9,15 @@ const errors = require("./errors");
 const logger = require("./logger");
 
 /**
- * Normalizes billing-account markup to the decimal format persisted on
+ * Normalizes billing-account markup to the multiplier format persisted on
  * challenges.
  *
- * Legacy project-service responses can return whole percentage points (for
- * example `50` for 50%), while newer billing-account records use decimal
- * fractions (for example `0.58` for 58%). This helper preserves modern values
- * and converts only legacy percentages.
+ * Billing-account records use the direct multiplier consumed by challenge,
+ * finance, and billing-account ledger math. Values greater than `1` are valid
+ * and must not be converted to percentage form.
  *
  * @param {unknown} rawMarkup Markup value returned by Projects API.
- * @returns {number|null} Decimal markup or `null` when the input is empty or invalid.
+ * @returns {number|null} Billing markup multiplier or `null` when the input is empty or invalid.
  */
 function normalizeBillingMarkup(rawMarkup) {
   if (_.isNil(rawMarkup) || rawMarkup === "") {
@@ -30,7 +29,7 @@ function normalizeBillingMarkup(rawMarkup) {
     return null;
   }
 
-  return markup > 1 ? markup / 100 : markup;
+  return markup;
 }
 
 /**
@@ -261,7 +260,7 @@ class ProjectHelper {
    * @param {string|number} params.billingAccountId Billing-account identifier.
    * @param {string} params.challengeId Challenge id to use as the external reference.
    * @param {number|string} params.memberPaymentAmount Challenge member-payment amount before markup.
-   * @param {number|string|null|undefined} params.markup Billing-account markup as a decimal or percentage.
+   * @param {number|string|null|undefined} params.markup Billing-account markup multiplier.
    * @returns {Promise<object>} Billing Accounts API lock response.
    * @throws {errors.BadRequestError} When required values are missing or invalid.
    * @throws {Error} When the Billing Accounts API rejects the lock request.
diff --git a/src/services/ChallengeService.js b/src/services/ChallengeService.js
index 2bb4b00..074404e 100644
--- a/src/services/ChallengeService.js
+++ b/src/services/ChallengeService.js
@@ -1956,7 +1956,6 @@ async function searchChallenges(currentUser, criteria) {
   const requestedMemberId = !_.isNil(criteria.memberId) ? _.toString(criteria.memberId) : null;
   const currentUserMemberId =
     currentUser && !_hasAdminRole && !_isMachineToken ? _.toString(currentUser.userId) : null;
-  const memberIdForTaskFilter = requestedMemberId || currentUserMemberId;
   const isSelfMemberSearch = Boolean(
     requestedMemberId && currentUserMemberId && requestedMemberId === currentUserMemberId,
   );
@@ -2078,27 +2077,11 @@ async function searchChallenges(currentUser, criteria) {
     });
   }
 
-  // FIXME: Tech Debt
-  let excludeTasks = true;
-  if (requestedMemberId) {
-    // When we already restrict the result set to a specific member,
-    // rerunning the generic task visibility filter is redundant.
-    excludeTasks = false;
-  } else if (
-    currentUser &&
-    (_hasAdminRole || _isMachineToken || hasProjectManagerAccessForSearch)
-  ) {
-    // if you're an admin or m2m, security rules wont be applied
-    excludeTasks = false;
-  }
-
   /**
-   * For non-authenticated users:
-   * - Only unassigned tasks will be returned
-   * For authenticated users (non-admin):
-   * - Only unassigned tasks and tasks assigned to the logged in user will be returned
-   * For admins/m2m:
-   * - All tasks will be returned
+   * Task challenges are visible to ordinary authenticated users only when they
+   * have a resource on the task. Anonymous users never receive tasks. Admin,
+   * machine-token and project-manager searches retain their operational access.
+   * A requested memberId narrows results but never grants the caller task access.
    */
   if (currentUser && (_hasAdminRole || _isMachineToken)) {
     // For admins/m2m, allow filtering based on task properties
@@ -2117,28 +2100,16 @@ async function searchChallenges(currentUser, criteria) {
         taskMemberId: criteria.taskMemberId,
       });
     }
-  } else if (excludeTasks) {
-    const taskFilter = [];
-    if (memberIdForTaskFilter) {
+  } else if (!hasProjectManagerAccessForSearch) {
+    const taskFilter = [{ taskIsTask: false }];
+    if (currentUserMemberId) {
       taskFilter.push({
+        taskIsTask: true,
         memberAccesses: {
-          some: { memberId: memberIdForTaskFilter },
+          some: { memberId: currentUserMemberId },
         },
       });
     }
-    taskFilter.push({
-      taskIsTask: false,
-    });
-    taskFilter.push({
-      taskIsTask: true,
-      taskIsAssigned: false,
-      taskMemberId: null,
-    });
-    if (currentUser && !_hasAdminRole && !_isMachineToken) {
-      taskFilter.push({
-        taskMemberId: currentUser.userId,
-      });
-    }
     prismaFilter.where.AND.push({
       OR: taskFilter,
     });
diff --git a/test/unit/ChallengeService.test.js b/test/unit/ChallengeService.test.js
index 6c5a47f..aa2a1ad 100644
--- a/test/unit/ChallengeService.test.js
+++ b/test/unit/ChallengeService.test.js
@@ -1006,6 +1006,71 @@ describe("challenge service unit tests", () => {
       should.equal(result.numOfRegistrants, 0);
     });
 
+    it("search challenges hides unassigned tasks from anonymous users", async () => {
+      await prisma.challenge.update({
+        where: { id: data.taskChallenge.id },
+        data: {
+          taskIsAssigned: false,
+          taskMemberId: null,
+        },
+      });
+
+      try {
+        const result = await service.searchChallenges(undefined, {
+          id: data.taskChallenge.id,
+        });
+
+        should.equal(result.total, 0);
+        should.equal(result.result.length, 0);
+      } finally {
+        await prisma.challenge.update({
+          where: { id: data.taskChallenge.id },
+          data: { taskIsAssigned: true },
+        });
+      }
+    });
+
+    it("search challenges uses the caller resource association for task visibility", async () => {
+      const originalGetCompleteUserGroupTreeIds = helper.getCompleteUserGroupTreeIds;
+      const originalMemberChallengeAccessFindMany = prisma.memberChallengeAccess.findMany;
+      const originalChallengeFindMany = prisma.challenge.findMany;
+      let capturedWhere;
+
+      helper.getCompleteUserGroupTreeIds = async () => [];
+      prisma.memberChallengeAccess.findMany = async () => [{ challengeId: data.taskChallenge.id }];
+      prisma.challenge.findMany = async (query) => {
+        capturedWhere = query.where;
+        return [];
+      };
+
+      try {
+        const result = await service.searchChallenges(
+          { roles: ["Topcoder User"], userId: "caller-resource-id" },
+          { memberId: "different-member-id" },
+        );
+
+        should.equal(result.total, 0);
+        const taskVisibilityFilter = capturedWhere.AND.find(
+          (filter) => filter.OR && filter.OR.some((condition) => condition.taskIsTask === false),
+        );
+        taskVisibilityFilter.should.deep.equal({
+          OR: [
+            { taskIsTask: false },
+            {
+              taskIsTask: true,
+              memberAccesses: {
+                some: { memberId: "caller-resource-id" },
+              },
+            },
+          ],
+        });
+      } finally {
+        helper.getCompleteUserGroupTreeIds = originalGetCompleteUserGroupTreeIds;
+        prisma.memberChallengeAccess.findMany = originalMemberChallengeAccessFindMany;
+        prisma.challenge.findMany = originalChallengeFindMany;
+      }
+    });
+
     it("search challenges sorts status alphabetically for member and non-member searches", async () => {
       const statusChallenges = [
         {
diff --git a/test/unit/project-helper.test.js b/test/unit/project-helper.test.js
index 7be1a10..3fbe9a9 100644
--- a/test/unit/project-helper.test.js
+++ b/test/unit/project-helper.test.js
@@ -41,13 +41,13 @@ describe('project helper unit tests', () => {
     })
   })
 
-  it('converts legacy whole-percentage billing markup to decimal format', async () => {
+  it('preserves billing markup multipliers greater than one', async () => {
     m2mHelper.getM2MToken = async () => 'test-token'
     axios.get = async () => ({
       status: 200,
       data: {
         tcBillingAccountId: '80004217',
-        markup: 58
+        markup: 1.2229
       }
     })
 
@@ -55,7 +55,7 @@ describe('project helper unit tests', () => {
 
     result.should.deep.equal({
       billingAccountId: '80004217',
-      markup: 0.58
+      markup: 1.2229
     })
   })
 
@@ -81,13 +81,13 @@ describe('project helper unit tests', () => {
     const result = await projectHelper.lockChallengeBillingAccountAmount({
       billingAccountId: '80001012',
       challengeId: 'challenge-id',
-      memberPaymentAmount: 1000,
-      markup: 0.1
+      memberPaymentAmount: 394,
+      markup: 1.2229
     })
 
     patchUrl.should.equal('http://localhost:4000/v6/billing-accounts/80001012/lock-amount')
     patchBody.should.deep.equal({
-      amount: 1100,
+      amount: 875.8226,
       challengeId: 'challenge-id',
       externalId: 'challenge-id',
       externalType: 'CHALLENGE'
@@ -95,7 +95,7 @@ describe('project helper unit tests', () => {
     patchHeaders.should.deep.equal({ Authorization: 'Bearer test-token' })
     result.should.deep.equal({
       externalId: 'challenge-id',
-      amount: 1100
+      amount: 875.8226
     })
   })
 })