diff --git a/addons/project/models/project.py b/addons/project/models/project.py
index 6c67bc69a2d..00faf9fed40 100644
--- a/addons/project/models/project.py
+++ b/addons/project/models/project.py
@@ -11,7 +11,7 @@ from random import randint
 from odoo import api, Command, fields, models, tools, SUPERUSER_ID, _
 from odoo.exceptions import UserError, ValidationError, AccessError
 from odoo.tools import format_amount
-from odoo.osv.expression import OR
+from odoo.osv.expression import OR, AND
 from odoo.tools.misc import get_lang
 
 from .project_task_recurrence import DAYS, WEEKS
@@ -2233,7 +2233,27 @@ class ProjectTags(models.Model):
 
     name = fields.Char('Name', required=True, translate=True)
     color = fields.Integer(string='Color', default=_get_default_color)
+    project_ids = fields.Many2many('project.project', 'project_project_project_tags_rel', string='Projects')
+    task_ids = fields.Many2many('project.task', string='Tasks')
 
     _sql_constraints = [
         ('name_uniq', 'unique (name)', "Tag name already exists!"),
     ]
+
+    @api.model
+    def _name_search(self, name='', args=None, operator='ilike', limit=100, name_get_uid=None):
+        domain = args
+        if 'project_id' in self.env.context:
+            project_id = self.env.context.get('project_id')
+            domain = AND([
+                domain,
+                ['|', ('task_ids.project_id', '=', project_id), ('project_ids', 'in', project_id)]
+            ])
+        return super()._name_search(name, domain, operator, limit, name_get_uid)
+
+    @api.model
+    def name_create(self, name):
+        existing_tag = self.search([('name', '=ilike', name.strip())], limit=1)
+        if existing_tag:
+            return existing_tag.name_get()[0]
+        return super().name_create(name)
diff --git a/addons/project/views/project_views.xml b/addons/project/views/project_views.xml
index 528be4cdb08..8dc9e751a2d 100644
--- a/addons/project/views/project_views.xml
+++ b/addons/project/views/project_views.xml
@@ -923,7 +923,7 @@
                             <field name="partner_id" widget="res_partner_many2one" class="o_task_customer_field"/>
                             <field name="partner_phone" widget="phone" attrs="{'invisible': True}"/>
                             <field name="date_deadline" attrs="{'invisible': [('is_closed', '=', True)]}"/>
-                            <field name="tag_ids" widget="many2many_tags" options="{'color_field': 'color', 'no_create_edit': True}"/>
+                            <field name="tag_ids" widget="many2many_tags" options="{'color_field': 'color', 'no_create_edit': True}" context="{'project_id': project_id}"/>
                             <field name="recurring_task" attrs="{'invisible': [('allow_recurring_tasks', '=', False)]}" />
                             <field name="legend_blocked" invisible="1"/>
                             <field name="legend_normal" invisible="1"/>
@@ -1210,7 +1210,7 @@
                     <field name="company_id" groups="base.group_multi_company" optional="show"/>
                     <field name="activity_ids" widget="list_activity" optional="show"/>
                     <field name="date_deadline" optional="hide" widget="remaining_days" attrs="{'invisible': [('is_closed', '=', True)]}"/>
-                    <field name="tag_ids" widget="many2many_tags" options="{'color_field': 'color'}" optional="show"/>
+                    <field name="tag_ids" widget="many2many_tags" options="{'color_field': 'color'}" optional="show" context="{'project_id': project_id}"/>
                     <field name="rating_last_text" string="Rating" decoration-danger="rating_last_text == 'ko'"
                         decoration-warning="rating_last_text == 'ok'" decoration-success="rating_last_text == 'top'"
                         attrs="{'invisible': [('rating_last_text', '=', 'none')]}"