diff --git a/addons/event_sale/models/event_registration.py b/addons/event_sale/models/event_registration.py
index 521f931d5ce..0d307ae2064 100644
--- a/addons/event_sale/models/event_registration.py
+++ b/addons/event_sale/models/event_registration.py
@@ -8,7 +8,6 @@ from odoo.tools import float_is_zero
 class EventRegistration(models.Model):
     _inherit = 'event.registration'
 
-    is_paid = fields.Boolean('Is Paid')
     # TDE FIXME: maybe add an onchange on sale_order_id
     sale_order_id = fields.Many2one('sale.order', string='Sales Order', ondelete='cascade', copy=False)
     sale_order_line_id = fields.Many2one('sale.order.line', string='Sales Order Line', ondelete='cascade', copy=False)
@@ -16,7 +15,7 @@ class EventRegistration(models.Model):
             ('to_pay', 'Not Paid'),
             ('paid', 'Paid'),
             ('free', 'Free'),
-        ], compute="_compute_payment_status", compute_sudo=True)
+        ], compute="_compute_payment_status", compute_sudo=True, store=True)
     utm_campaign_id = fields.Many2one(compute='_compute_utm_campaign_id', readonly=False,
         store=True, ondelete="set null")
     utm_source_id = fields.Many2one(compute='_compute_utm_source_id', readonly=False,
@@ -24,17 +23,13 @@ class EventRegistration(models.Model):
     utm_medium_id = fields.Many2one(compute='_compute_utm_medium_id', readonly=False,
         store=True, ondelete="set null")
 
-    @api.depends('is_paid', 'sale_order_id.currency_id', 'sale_order_line_id.price_total')
+    @api.depends('sale_order_id.state', 'sale_order_id.currency_id', 'sale_order_line_id.price_total')
     def _compute_payment_status(self):
-        for record in self:
-            so = record.sale_order_id
-            so_line = record.sale_order_line_id
-            if not so or float_is_zero(so_line.price_total, precision_digits=so.currency_id.rounding):
-                record.payment_status = 'free'
-            elif record.is_paid:
-                record.payment_status = 'paid'
+        for so_line, registrations in self.grouped('sale_order_line_id').items():
+            if not so_line or float_is_zero(so_line.price_total, precision_digits=so_line.currency_id.rounding):
+                registrations.payment_status = 'free'
             else:
-                record.payment_status = 'to_pay'
+                registrations.payment_status = 'to_pay'
 
     @api.depends('sale_order_id')
     def _compute_utm_campaign_id(self):
@@ -125,7 +120,7 @@ class EventRegistration(models.Model):
                 render_context=render_context)
 
     def _action_set_paid(self):
-        self.write({'is_paid': True})
+        self.write({'payment_status': 'paid'})
 
     def _get_registration_summary(self):
         res = super(EventRegistration, self)._get_registration_summary()
diff --git a/addons/event_sale/models/sale_order_line.py b/addons/event_sale/models/sale_order_line.py
index 86ae6787c35..05cf43caa5c 100644
--- a/addons/event_sale/models/sale_order_line.py
+++ b/addons/event_sale/models/sale_order_line.py
@@ -36,7 +36,7 @@ class SaleOrderLine(models.Model):
             if confirm:
                 existing_registrations.filtered(lambda self: self.state not in ['open', 'cancel']).action_confirm()
             if mark_as_paid:
-                existing_registrations.filtered(lambda self: not self.is_paid)._action_set_paid()
+                existing_registrations.filtered(lambda self: self.payment_status == 'to_pay')._action_set_paid()
             if cancel_to_draft:
                 existing_registrations.filtered(lambda self: self.state == 'cancel').action_set_draft()
 
diff --git a/addons/event_sale/report/event_sale_report.py b/addons/event_sale/report/event_sale_report.py
index 799aa2fcaf5..7bb64ad7db3 100644
--- a/addons/event_sale/report/event_sale_report.py
+++ b/addons/event_sale/report/event_sale_report.py
@@ -39,7 +39,6 @@ class EventSaleReport(models.Model):
     sale_price = fields.Float('Revenues', readonly=True)
     sale_price_untaxed = fields.Float('Untaxed Revenues', readonly=True)
     invoice_partner_id = fields.Many2one('res.partner', string='Invoice Address', readonly=True)
-    is_paid = fields.Boolean('Is Paid', readonly=True)
     payment_status = fields.Selection(string="Payment Status", selection=[
             ('to_pay', 'Not Paid'),
             ('paid', 'Paid'),
@@ -81,7 +80,7 @@ SELECT
     event_registration.active AS active,
     event_registration.sale_order_id AS sale_order_id,
     event_registration.sale_order_line_id AS sale_order_line_id,
-    event_registration.is_paid AS is_paid,
+    event_registration.payment_status AS payment_status,
 
     event_event.event_type_id AS event_type_id,
     event_event.date_begin AS event_date_begin,
@@ -109,12 +108,7 @@ SELECT
         sale_order_line.price_subtotal
             / CASE COALESCE(sale_order.currency_rate, 0) WHEN 0 THEN 1.0 ELSE sale_order.currency_rate END
             / sale_order_line.product_uom_qty
-        END AS sale_price_untaxed,
-    CASE
-        WHEN sale_order_line.price_total = 0 THEN 'free'
-        WHEN event_registration.is_paid THEN 'paid'
-        ELSE 'to_pay'
-    END payment_status""" + (',\n    ' + ',\n    '.join(select) if select else '')
+    END AS sale_price_untaxed""" + (',\n    ' + ',\n    '.join(select) if select else '')
 
     def _from_clause(self, *join_):
         # Extra clauses formatted as `column1`, `column2`...
diff --git a/addons/event_sale/views/event_registration_views.xml b/addons/event_sale/views/event_registration_views.xml
index bb9cd5b3285..9464d03aed1 100644
--- a/addons/event_sale/views/event_registration_views.xml
+++ b/addons/event_sale/views/event_registration_views.xml
@@ -48,8 +48,8 @@
                 <field name="sale_order_id" invisible="1"/>
             </xpath>
             <xpath expr="//group" position="before">
-                <field name="is_paid" invisible="1"/>
-                <widget name="web_ribbon" title="Paid" bg_color="text-bg-success" invisible="not is_paid"/>
+                <field name="payment_status" invisible="1"/>
+                <widget name="web_ribbon" title="Paid" bg_color="text-bg-success" invisible="payment_status != 'paid'"/>
             </xpath>
             <group name="utm_link" position="before">
                 <group string="Transaction" groups="base.group_no_one">