diff --git a/README.md b/README.md
index 13f5f4ea..13ce0505 100644
--- a/README.md
+++ b/README.md
@@ -62,7 +62,6 @@ The following parameters can be set in config files or in env variables:
 - ES.ES_REFRESH: Elasticsearch refresh method. Default to string `true`(i.e. refresh immediately)
 - FILE_UPLOAD_SIZE_LIMIT: the file upload size limit in bytes
 - RESOURCES_API_URL: TC resources API base URL
-- V3_PROJECTS_API_URL: TC direct projects API base URL
 - GROUPS_API_URL: TC groups API base URL
 - PROJECTS_API_URL: TC projects API base URL
 - TERMS_API_URL: TC Terms API Base URL
diff --git a/config/default.js b/config/default.js
index bd64f4eb..1fd2d89a 100644
--- a/config/default.js
+++ b/config/default.js
@@ -54,7 +54,6 @@ module.exports = {
   GROUPS_API_URL: process.env.GROUPS_API_URL || 'http://localhost:4000/v5/groups',
   PROJECTS_API_URL: process.env.PROJECTS_API_URL || 'http://localhost:4000/v5/projects',
   TERMS_API_URL: process.env.TERMS_API_URL || 'http://localhost:4000/v5/terms',
-  V3_PROJECTS_API_URL: process.env.V3_PROJECTS_API_URL || 'http://localhost:4000/v3/direct/projects',
   // copilot resource role ids allowed to upload attachment
   COPILOT_RESOURCE_ROLE_IDS: process.env.COPILOT_RESOURCE_ROLE_IDS
     ? process.env.COPILOT_RESOURCE_ROLE_IDS.split(',') : ['10ba038e-48da-487b-96e8-8d3b99b6d18b'],
diff --git a/src/common/helper.js b/src/common/helper.js
index 4802b102..513af441 100644
--- a/src/common/helper.js
+++ b/src/common/helper.js
@@ -759,10 +759,10 @@ async function getProjectDefaultTerms (projectId) {
  */
 async function getProjectBillingAccount (projectId) {
   const token = await getM2MToken()
-  const projectUrl = `${config.V3_PROJECTS_API_URL}/${projectId}`
+  const projectUrl = `${config.PROJECTS_API_URL}/${projectId}`
   try {
     const res = await axios.get(projectUrl, { headers: { Authorization: `Bearer ${token}` } })
-    return _.get(res, 'data.result.content.billingAccountIds[0]', null)
+    return _.get(res, 'data.billingAccountId', null)
   } catch (err) {
     if (_.get(err, 'response.status') === HttpStatus.NOT_FOUND) {
       throw new errors.BadRequestError(`Project with id: ${projectId} doesn't exist`)
diff --git a/src/services/ChallengeService.js b/src/services/ChallengeService.js
index 3805556b..757145c2 100644
--- a/src/services/ChallengeService.js
+++ b/src/services/ChallengeService.js
@@ -1209,7 +1209,7 @@ async function update (currentUser, challengeId, data, isFull) {
       if (!_.get(challenge, 'legacy.pureV5Task') && _.isUndefined(_.get(challenge, 'legacy.directProjectId'))) {
         throw new errors.BadRequestError('You cannot activate the challenge as it has not been created on legacy yet. Please try again later or contact support.')
       }
-      billingAccountId = await helper.getProjectBillingAccount(_.get(challenge, 'legacy.directProjectId'))
+      billingAccountId = await helper.getProjectBillingAccount(_.get(challenge, 'projectId'))
       // if activating a challenge, the challenge must have a billing account id
       if ((!billingAccountId || billingAccountId === null) &&
         challenge.status === constants.challengeStatuses.Draft) {
@@ -1220,7 +1220,7 @@ async function update (currentUser, challengeId, data, isFull) {
       if (challenge.status !== constants.challengeStatuses.Active) {
         throw new errors.BadRequestError('You cannot mark a Draft challenge as Completed')
       }
-      billingAccountId = await helper.getProjectBillingAccount(_.get(challenge, 'legacy.directProjectId'))
+      billingAccountId = await helper.getProjectBillingAccount(_.get(challenge, 'projectId'))
     }
   }