diff --git a/src/app/app.guard.ts b/src/app/app.guard.ts
index 61076a26a7..955386d7f0 100644
--- a/src/app/app.guard.ts
+++ b/src/app/app.guard.ts
@@ -2,21 +2,24 @@ import {Injectable} from '@angular/core';
 import {ActivatedRouteSnapshot, CanActivate, Router, RouterStateSnapshot} from '@angular/router';
 import {WorkContextService} from './features/work-context/work-context.service';
 import {Observable, of} from 'rxjs';
-import {switchMap, take} from 'rxjs/operators';
+import {concatMap, map, switchMap, take, tap} from 'rxjs/operators';
 import {WorkContextType} from './features/work-context/work-context.model';
+import {TagService} from './features/tag/tag.service';
+import {ProjectService} from './features/project/project.service';
+import {DataInitService} from './core/data-init/data-init.service';
 
 @Injectable({
   providedIn: 'root'
 })
 export class ActiveWorkContextGuard implements CanActivate {
   constructor(
-    private workContextService: WorkContextService,
-    private router: Router,
+    private _workContextService: WorkContextService,
+    private _router: Router,
   ) {
   }
 
   canActivate(next: ActivatedRouteSnapshot, state: RouterStateSnapshot): Observable<any> {
-    return this.workContextService.activeWorkContextTypeAndId$.pipe(
+    return this._workContextService.activeWorkContextTypeAndId$.pipe(
       take(1),
       switchMap(({activeType, activeId}) => {
         const {subPageType, param} = next.params;
@@ -24,8 +27,50 @@ export class ActiveWorkContextGuard implements CanActivate {
           ? 'tag'
           : 'project';
         const url = `/${base}/${activeId}/${subPageType}${param ? '/' + param : ''}`;
-        return of(this.router.parseUrl(url));
+        return of(this._router.parseUrl(url));
       })
     );
   }
 }
+
+
+@Injectable({
+  providedIn: 'root'
+})
+export class ValidTagIdGuard implements CanActivate {
+  constructor(
+    private _router: Router,
+    private _tagService: TagService,
+    private _dataInitService: DataInitService,
+  ) {
+  }
+
+  canActivate(next: ActivatedRouteSnapshot, state: RouterStateSnapshot): Observable<boolean> {
+    const {id} = next.params;
+    return this._dataInitService.isAllDataLoadedInitially$.pipe(
+      concatMap(() => this._tagService.getTagById$(id)),
+      take(1),
+      map(tag => !!tag),
+    );
+  }
+}
+
+@Injectable({
+  providedIn: 'root'
+})
+export class ValidProjectIdGuard implements CanActivate {
+  constructor(
+    private _router: Router,
+    private _projectService: ProjectService,
+    private _dataInitService: DataInitService,
+  ) {
+  }
+
+  canActivate(next: ActivatedRouteSnapshot, state: RouterStateSnapshot): Observable<boolean> {
+    const {id} = next.params;
+    return this._dataInitService.isAllDataLoadedInitially$.pipe(
+      concatMap(() => this._projectService.getByIdOnce$(id)),
+      map(project => !!project),
+    );
+  }
+}
diff --git a/src/app/app.routes.ts b/src/app/app.routes.ts
index e2c3ae4201..9e887642e4 100644
--- a/src/app/app.routes.ts
+++ b/src/app/app.routes.ts
@@ -9,7 +9,7 @@ import {ProcrastinationComponent} from './features/procrastination/procrastinati
 import {SchedulePageComponent} from './pages/schedule-page/schedule-page.component';
 import {ProjectSettingsPageComponent} from './pages/project-settings-page/project-settings-page.component';
 import {TagTaskPageComponent} from './pages/tag-task-page/tag-task-page.component';
-import {ActiveWorkContextGuard} from './app.guard';
+import {ActiveWorkContextGuard, ValidProjectIdGuard, ValidTagIdGuard} from './app.guard';
 import {TagSettingsPageComponent} from './pages/tag-settings-page/tag-settings-page.component';
 
 export const APP_ROUTES: Routes = [
@@ -17,19 +17,74 @@ export const APP_ROUTES: Routes = [
   {path: 'schedule', component: SchedulePageComponent, data: {page: 'schedule'}},
   {path: 'procrastination', component: ProcrastinationComponent, data: {page: 'procrastination'}},
 
-  {path: 'tag/:id/tasks', component: TagTaskPageComponent, data: {page: 'tag-tasks'}},
-  {path: 'tag/:id/settings', component: TagSettingsPageComponent, data: {page: 'tag-settings'}},
-  {path: 'tag/:id/worklog', component: WorklogComponent, data: {page: 'worklog'}},
-  // {path: 'tag/:id/metrics', component: MetricPageComponent, data: {page: 'metrics'}},
-  {path: 'tag/:id/daily-summary', component: DailySummaryComponent, data: {page: 'daily-summary'}},
-  {path: 'tag/:id/daily-summary/:dayStr', component: DailySummaryComponent, data: {page: 'daily-summary'}},
+  {
+    path: 'tag/:id/tasks',
+    component: TagTaskPageComponent,
+    data: {page: 'tag-tasks'},
+    canActivate: [ValidTagIdGuard]
+  },
+  {
+    path: 'tag/:id/settings',
+    component: TagSettingsPageComponent,
+    data: {page: 'tag-settings'},
+    canActivate: [ValidTagIdGuard]
+  },
+  {
+    path: 'tag/:id/worklog',
+    component: WorklogComponent,
+    data: {page: 'worklog'},
+    canActivate: [ValidTagIdGuard]
+  },
+  // {path: 'tag/:id/metrics', component: MetricPageComponent, data: {page: 'metrics'}, canActivate: [ValidContextIdGuard]},
+  {
+    path: 'tag/:id/daily-summary',
+    component: DailySummaryComponent,
+    data: {page: 'daily-summary'},
+    canActivate: [ValidTagIdGuard]
+  },
+  {
+    path: 'tag/:id/daily-summary/:dayStr',
+    component: DailySummaryComponent,
+    data: {page: 'daily-summary'},
+    canActivate: [ValidTagIdGuard]
+  },
 
-  {path: 'project/:id/tasks', component: ProjectTaskPageComponent, data: {page: 'project-tasks'}},
-  {path: 'project/:id/settings', component: ProjectSettingsPageComponent, data: {page: 'project-settings'}},
-  {path: 'project/:id/worklog', component: WorklogComponent, data: {page: 'worklog'}},
-  {path: 'project/:id/metrics', component: MetricPageComponent, data: {page: 'metrics'}},
-  {path: 'project/:id/daily-summary', component: DailySummaryComponent, data: {page: 'daily-summary'}},
-  {path: 'project/:id/daily-summary/:dayStr', component: DailySummaryComponent, data: {page: 'daily-summary'}},
+  {
+    path: 'project/:id/tasks',
+    component: ProjectTaskPageComponent,
+    data: {page: 'project-tasks'},
+    canActivate: [ValidProjectIdGuard]
+  },
+  {
+    path: 'project/:id/settings',
+    component: ProjectSettingsPageComponent,
+    data: {page: 'project-settings'},
+    canActivate: [ValidProjectIdGuard]
+  },
+  {
+    path: 'project/:id/worklog',
+    component: WorklogComponent,
+    data: {page: 'worklog'},
+    canActivate: [ValidProjectIdGuard]
+  },
+  {
+    path: 'project/:id/metrics',
+    component: MetricPageComponent,
+    data: {page: 'metrics'},
+    canActivate: [ValidProjectIdGuard]
+  },
+  {
+    path: 'project/:id/daily-summary',
+    component: DailySummaryComponent,
+    data: {page: 'daily-summary'},
+    canActivate: [ValidProjectIdGuard]
+  },
+  {
+    path: 'project/:id/daily-summary/:dayStr',
+    component: DailySummaryComponent,
+    data: {page: 'daily-summary'},
+    canActivate: [ValidProjectIdGuard]
+  },
   {path: 'project-overview', component: ProjectOverviewPageComponent, data: {page: 'project-overview'}},
 
 
diff --git a/src/app/features/work-context/work-context.service.ts b/src/app/features/work-context/work-context.service.ts
index b916cbb6af..f3102b53b9 100644
--- a/src/app/features/work-context/work-context.service.ts
+++ b/src/app/features/work-context/work-context.service.ts
@@ -457,8 +457,11 @@ export class WorkContextService {
   }
 
   // NOTE: NEVER call this from some place other than the route change stuff
-  private _setActiveContext(activeId: string, activeType: WorkContextType) {
+  private async _setActiveContext(activeId: string, activeType: WorkContextType) {
     this._store$.dispatch(setActiveWorkContext({activeId, activeType}));
   }
 
+  private async _isValidContextId(id: string): Promise<boolean> {
+
+  }
 }