diff --git a/apps/browser/src/_locales/en/messages.json b/apps/browser/src/_locales/en/messages.json
index 5244fed76ef..f5b3e798aff 100644
--- a/apps/browser/src/_locales/en/messages.json
+++ b/apps/browser/src/_locales/en/messages.json
@@ -1965,13 +1965,9 @@
   "apiKey": {
     "message": "API Key"
   },
-  "accountId": {
-    "message": "Account ID",
-    "description": "ID is short for 'Identifier'"
-  },
   "ssoKeyConnectorError": {
     "message": "Key Connector error: make sure Key Connector is available and working correctly."
-  }, 
+  },
   "premiumSubcriptionRequired": {
     "message": "Premium subscription required"
   },
diff --git a/apps/browser/src/popup/generator/generator.component.html b/apps/browser/src/popup/generator/generator.component.html
index 5a9a067a4e1..c3ae6c6ab53 100644
--- a/apps/browser/src/popup/generator/generator.component.html
+++ b/apps/browser/src/popup/generator/generator.component.html
@@ -401,21 +401,11 @@
             <input
               id="fastmail-apiToken"
               type="password"
-              name="FastMailApiToken"
+              name="FastmailApiToken"
               [(ngModel)]="usernameOptions.forwardedFastmailApiToken"
               (blur)="saveUsernameOptions()"
             />
           </div>
-          <div class="box-content-row" appBoxRow>
-            <label for="fastmail-accountId">{{ "accountId" | i18n }}</label>
-            <input
-              id="fastmail-accountId"
-              type="text"
-              name="FastmailAccountId"
-              [(ngModel)]="usernameOptions.forwardedFastmailAccountId"
-              (blur)="saveUsernameOptions()"
-            />
-          </div>
         </ng-container>
       </div>
     </div>
diff --git a/apps/desktop/src/app/vault/generator.component.html b/apps/desktop/src/app/vault/generator.component.html
index 79e66ae5366..6fdd33f0fab 100644
--- a/apps/desktop/src/app/vault/generator.component.html
+++ b/apps/desktop/src/app/vault/generator.component.html
@@ -434,21 +434,11 @@
                   <input
                     id="fastmail-apiToken"
                     type="password"
-                    name="FastMailApiToken"
+                    name="FastmailApiToken"
                     [(ngModel)]="usernameOptions.forwardedFastmailApiToken"
                     (blur)="saveUsernameOptions()"
                   />
                 </div>
-                <div class="box-content-row" appBoxRow>
-                  <label for="fastmail-accountId">{{ "accountId" | i18n }}</label>
-                  <input
-                    id="fastmail-accountId"
-                    type="text"
-                    name="FastmailAccountId"
-                    [(ngModel)]="usernameOptions.forwardedFastmailAccountId"
-                    (blur)="saveUsernameOptions()"
-                  />
-                </div>
               </ng-container>
             </div>
           </div>
diff --git a/apps/desktop/src/locales/en/messages.json b/apps/desktop/src/locales/en/messages.json
index 04fd939c77c..e399281c061 100644
--- a/apps/desktop/src/locales/en/messages.json
+++ b/apps/desktop/src/locales/en/messages.json
@@ -1982,10 +1982,6 @@
   "premiumSubcriptionRequired": {
     "message": "Premium subscription required"
   },
-  "accountId": {
-    "message": "Account ID",
-    "description": "ID is short for 'Identifier'"
-  },
   "organizationIsDisabled": {
     "message": "Organization is disabled."
   },
diff --git a/apps/web/src/app/tools/generator.component.html b/apps/web/src/app/tools/generator.component.html
index 67d23e61463..542c0c3c5e3 100644
--- a/apps/web/src/app/tools/generator.component.html
+++ b/apps/web/src/app/tools/generator.component.html
@@ -354,16 +354,6 @@
           (blur)="saveUsernameOptions()"
         />
       </div>
-      <div class="form-group col-4">
-        <label for="fastmail-accountId">{{ "accountId" | i18n }}</label>
-        <input
-          id="fastmail-accountId"
-          class="form-control"
-          type="text"
-          [(ngModel)]="usernameOptions.forwardedFastmailAccountId"
-          (blur)="saveUsernameOptions()"
-        />
-      </div>
     </div>
   </ng-container>
   <div class="row" *ngIf="usernameOptions.type === 'subaddress'">
diff --git a/apps/web/src/locales/en/messages.json b/apps/web/src/locales/en/messages.json
index fa2a98f4e54..0e711752773 100644
--- a/apps/web/src/locales/en/messages.json
+++ b/apps/web/src/locales/en/messages.json
@@ -5312,9 +5312,5 @@
   },
   "numberOfUsers": {
     "message": "Number of users"
-  },
-  "accountId": {
-    "message": "Account ID",
-    "description": "ID is short for 'Identifier'"
   }
 }
diff --git a/libs/angular/src/components/generator.component.ts b/libs/angular/src/components/generator.component.ts
index 15905632e45..90e5864dcbf 100644
--- a/libs/angular/src/components/generator.component.ts
+++ b/libs/angular/src/components/generator.component.ts
@@ -74,7 +74,7 @@ export class GeneratorComponent implements OnInit {
       { name: "SimpleLogin", value: "simplelogin" },
       { name: "AnonAddy", value: "anonaddy" },
       { name: "Firefox Relay", value: "firefoxrelay" },
-      { name: "FastMail", value: "fastmail" },
+      { name: "Fastmail", value: "fastmail" },
       { name: "DuckDuckGo", value: "duckduckgo" },
     ];
   }
diff --git a/libs/common/src/emailForwarders/fastmailForwarder.ts b/libs/common/src/emailForwarders/fastmailForwarder.ts
index 9e7dcbb7467..545a0c700a0 100644
--- a/libs/common/src/emailForwarders/fastmailForwarder.ts
+++ b/libs/common/src/emailForwarders/fastmailForwarder.ts
@@ -8,9 +8,12 @@ export class FastmailForwarder implements Forwarder {
     if (options.apiKey == null || options.apiKey === "") {
       throw "Invalid Fastmail API token.";
     }
-    if (options?.fastmail.accountId == null || options.fastmail.accountId === "") {
-      throw "Invalid Fastmail account ID.";
+
+    const accountId = await this.getAccountId(apiService, options);
+    if (accountId == null || accountId === "") {
+      throw "Unable to obtain Fastmail masked email account ID.";
     }
+
     const requestInit: RequestInit = {
       redirect: "manual",
       cache: "no-store",
@@ -27,13 +30,11 @@ export class FastmailForwarder implements Forwarder {
         [
           "MaskedEmail/set",
           {
-            accountId: "u" + options.fastmail.accountId,
+            accountId: accountId,
             create: {
               "new-masked-email": {
                 state: "enabled",
-                description:
-                  (options.website != null ? options.website + " - " : "") +
-                  "Generated by Bitwarden",
+                description: "",
                 url: options.website,
                 emailPrefix: options.fastmail.prefix,
               },
@@ -59,9 +60,29 @@ export class FastmailForwarder implements Forwarder {
         }
       }
     }
-    if (response.status === 401) {
+    if (response.status === 401 || response.status === 403) {
       throw "Invalid Fastmail API token.";
     }
     throw "Unknown Fastmail error occurred.";
   }
+
+  private async getAccountId(apiService: ApiService, options: ForwarderOptions): Promise<string> {
+    const requestInit: RequestInit = {
+      cache: "no-store",
+      method: "GET",
+      headers: new Headers({
+        Authorization: "Bearer " + options.apiKey,
+      }),
+    };
+    const url = "https://api.fastmail.com/.well-known/jmap";
+    const request = new Request(url, requestInit);
+    const response = await apiService.nativeFetch(request);
+    if (response.status === 200) {
+      const json = await response.json();
+      if (json.primaryAccounts != null) {
+        return json.primaryAccounts["https://www.fastmail.com/dev/maskedemail"];
+      }
+    }
+    return null;
+  }
 }
diff --git a/libs/common/src/emailForwarders/forwarderOptions.ts b/libs/common/src/emailForwarders/forwarderOptions.ts
index 7482f82e496..ef5311f0d7d 100644
--- a/libs/common/src/emailForwarders/forwarderOptions.ts
+++ b/libs/common/src/emailForwarders/forwarderOptions.ts
@@ -6,7 +6,6 @@ export class ForwarderOptions {
 }
 
 export class FastmailForwarderOptions {
-  accountId: string;
   prefix: string;
 }
 
diff --git a/libs/common/src/services/usernameGeneration.service.ts b/libs/common/src/services/usernameGeneration.service.ts
index 3ad2c513403..7a5abd4f7de 100644
--- a/libs/common/src/services/usernameGeneration.service.ts
+++ b/libs/common/src/services/usernameGeneration.service.ts
@@ -131,7 +131,6 @@ export class UsernameGenerationService implements BaseUsernameGenerationService
     } else if (o.forwardedService === "fastmail") {
       forwarder = new FastmailForwarder();
       forwarderOptions.apiKey = o.forwardedFastmailApiToken;
-      forwarderOptions.fastmail.accountId = o.forwardedFastmailAccountId;
     } else if (o.forwardedService === "duckduckgo") {
       forwarder = new DuckDuckGoForwarder();
       forwarderOptions.apiKey = o.forwardedDuckDuckGoToken;