diff --git a/ddl/02-enums.sql b/ddl/02-enums.sql
index 9027c06..d772724 100644
--- a/ddl/02-enums.sql
+++ b/ddl/02-enums.sql
@@ -62,3 +62,10 @@ CREATE TYPE webhooks.event_type AS ENUM (
 CREATE TYPE whatsapp.message_status AS ENUM ('pending', 'sent', 'delivered', 'read', 'failed');
 CREATE TYPE whatsapp.message_type AS ENUM ('text', 'template', 'image', 'document', 'audio', 'video', 'location', 'contacts', 'interactive');
 CREATE TYPE whatsapp.message_direction AS ENUM ('outbound', 'inbound');
+
+-- Sales enums (SAAS-018)
+CREATE TYPE sales.lead_status AS ENUM ('new', 'contacted', 'qualified', 'unqualified', 'converted');
+CREATE TYPE sales.lead_source AS ENUM ('website', 'referral', 'cold_call', 'event', 'advertisement', 'social_media', 'other');
+CREATE TYPE sales.opportunity_stage AS ENUM ('prospecting', 'qualification', 'proposal', 'negotiation', 'closed_won', 'closed_lost');
+CREATE TYPE sales.activity_type AS ENUM ('call', 'meeting', 'task', 'email', 'note');
+CREATE TYPE sales.activity_status AS ENUM ('pending', 'completed', 'cancelled');
diff --git a/ddl/schemas/sales/00-schema.sql b/ddl/schemas/sales/00-schema.sql
new file mode 100644
index 0000000..974e5a1
--- /dev/null
+++ b/ddl/schemas/sales/00-schema.sql
@@ -0,0 +1,19 @@
+-- ============================================
+-- TEMPLATE-SAAS: Sales Schema
+-- Version: 1.0.0
+-- Module: SAAS-018
+-- ============================================
+
+-- Create schema
+CREATE SCHEMA IF NOT EXISTS sales;
+
+-- Grant permissions
+GRANT USAGE ON SCHEMA sales TO template_saas_app;
+GRANT ALL PRIVILEGES ON ALL TABLES IN SCHEMA sales TO template_saas_app;
+GRANT ALL PRIVILEGES ON ALL SEQUENCES IN SCHEMA sales TO template_saas_app;
+
+-- Default privileges for future tables
+ALTER DEFAULT PRIVILEGES IN SCHEMA sales
+  GRANT ALL PRIVILEGES ON TABLES TO template_saas_app;
+ALTER DEFAULT PRIVILEGES IN SCHEMA sales
+  GRANT ALL PRIVILEGES ON SEQUENCES TO template_saas_app;
diff --git a/ddl/schemas/sales/01-enums.sql b/ddl/schemas/sales/01-enums.sql
new file mode 100644
index 0000000..3766397
--- /dev/null
+++ b/ddl/schemas/sales/01-enums.sql
@@ -0,0 +1,51 @@
+-- ============================================
+-- TEMPLATE-SAAS: Sales Enums
+-- Version: 1.0.0
+-- Module: SAAS-018
+-- ============================================
+
+-- Lead status enum
+CREATE TYPE sales.lead_status AS ENUM (
+  'new',
+  'contacted',
+  'qualified',
+  'unqualified',
+  'converted'
+);
+
+-- Lead source enum
+CREATE TYPE sales.lead_source AS ENUM (
+  'website',
+  'referral',
+  'cold_call',
+  'event',
+  'advertisement',
+  'social_media',
+  'other'
+);
+
+-- Opportunity stage enum
+CREATE TYPE sales.opportunity_stage AS ENUM (
+  'prospecting',
+  'qualification',
+  'proposal',
+  'negotiation',
+  'closed_won',
+  'closed_lost'
+);
+
+-- Activity type enum
+CREATE TYPE sales.activity_type AS ENUM (
+  'call',
+  'meeting',
+  'task',
+  'email',
+  'note'
+);
+
+-- Activity status enum
+CREATE TYPE sales.activity_status AS ENUM (
+  'pending',
+  'completed',
+  'cancelled'
+);
diff --git a/ddl/schemas/sales/02-tables.sql b/ddl/schemas/sales/02-tables.sql
new file mode 100644
index 0000000..751f5e6
--- /dev/null
+++ b/ddl/schemas/sales/02-tables.sql
@@ -0,0 +1,243 @@
+-- ============================================
+-- TEMPLATE-SAAS: Sales Tables
+-- Version: 1.0.0
+-- Module: SAAS-018
+-- ============================================
+
+-- ============================================
+-- Pipeline Stages (configurable stages per tenant)
+-- ============================================
+CREATE TABLE sales.pipeline_stages (
+    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    tenant_id UUID NOT NULL REFERENCES tenants.tenants(id) ON DELETE CASCADE,
+
+    -- Stage info
+    name VARCHAR(100) NOT NULL,
+    position INT NOT NULL DEFAULT 0,
+    color VARCHAR(7) DEFAULT '#3B82F6',
+
+    -- Stage type flags
+    is_won BOOLEAN DEFAULT FALSE,
+    is_lost BOOLEAN DEFAULT FALSE,
+    is_active BOOLEAN DEFAULT TRUE,
+
+    -- Audit
+    created_at TIMESTAMPTZ DEFAULT NOW() NOT NULL,
+    updated_at TIMESTAMPTZ DEFAULT NOW() NOT NULL,
+
+    -- Constraints
+    CONSTRAINT unique_stage_position UNIQUE (tenant_id, position),
+    CONSTRAINT check_win_lost_exclusive CHECK (NOT (is_won AND is_lost))
+);
+
+COMMENT ON TABLE sales.pipeline_stages IS 'Configurable pipeline stages per tenant';
+
+-- ============================================
+-- Leads (prospects)
+-- ============================================
+CREATE TABLE sales.leads (
+    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    tenant_id UUID NOT NULL REFERENCES tenants.tenants(id) ON DELETE CASCADE,
+
+    -- Contact info
+    first_name VARCHAR(100) NOT NULL,
+    last_name VARCHAR(100) NOT NULL,
+    email VARCHAR(255),
+    phone VARCHAR(50),
+
+    -- Company info
+    company VARCHAR(200),
+    job_title VARCHAR(150),
+    website VARCHAR(255),
+
+    -- Lead classification
+    source sales.lead_source DEFAULT 'other',
+    status sales.lead_status DEFAULT 'new' NOT NULL,
+    score INT DEFAULT 0 CHECK (score >= 0 AND score <= 100),
+
+    -- Assignment
+    assigned_to UUID REFERENCES users.users(id) ON DELETE SET NULL,
+
+    -- Notes
+    notes TEXT,
+
+    -- Conversion tracking
+    converted_at TIMESTAMPTZ,
+    converted_to_opportunity_id UUID,
+
+    -- Address
+    address_line1 VARCHAR(255),
+    address_line2 VARCHAR(255),
+    city VARCHAR(100),
+    state VARCHAR(100),
+    postal_code VARCHAR(20),
+    country VARCHAR(100),
+
+    -- Custom fields (JSON)
+    custom_fields JSONB DEFAULT '{}'::jsonb,
+
+    -- Audit
+    created_at TIMESTAMPTZ DEFAULT NOW() NOT NULL,
+    updated_at TIMESTAMPTZ DEFAULT NOW() NOT NULL,
+    created_by UUID REFERENCES users.users(id) ON DELETE SET NULL,
+    deleted_at TIMESTAMPTZ
+);
+
+COMMENT ON TABLE sales.leads IS 'Sales leads/prospects';
+COMMENT ON COLUMN sales.leads.score IS 'Lead score from 0-100';
+COMMENT ON COLUMN sales.leads.custom_fields IS 'Flexible custom fields per tenant';
+
+-- ============================================
+-- Opportunities (deals)
+-- ============================================
+CREATE TABLE sales.opportunities (
+    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    tenant_id UUID NOT NULL REFERENCES tenants.tenants(id) ON DELETE CASCADE,
+
+    -- Basic info
+    name VARCHAR(255) NOT NULL,
+    description TEXT,
+
+    -- Lead reference (optional)
+    lead_id UUID REFERENCES sales.leads(id) ON DELETE SET NULL,
+
+    -- Pipeline stage
+    stage sales.opportunity_stage DEFAULT 'prospecting' NOT NULL,
+    stage_id UUID REFERENCES sales.pipeline_stages(id) ON DELETE SET NULL,
+
+    -- Value
+    amount DECIMAL(15, 2) DEFAULT 0,
+    currency VARCHAR(3) DEFAULT 'USD',
+    probability INT DEFAULT 0 CHECK (probability >= 0 AND probability <= 100),
+
+    -- Timeline
+    expected_close_date DATE,
+    actual_close_date DATE,
+
+    -- Assignment
+    assigned_to UUID REFERENCES users.users(id) ON DELETE SET NULL,
+
+    -- Win/Loss tracking
+    won_at TIMESTAMPTZ,
+    lost_at TIMESTAMPTZ,
+    lost_reason VARCHAR(500),
+
+    -- Contact info (can be different from lead)
+    contact_name VARCHAR(200),
+    contact_email VARCHAR(255),
+    contact_phone VARCHAR(50),
+    company_name VARCHAR(200),
+
+    -- Notes
+    notes TEXT,
+
+    -- Custom fields
+    custom_fields JSONB DEFAULT '{}'::jsonb,
+
+    -- Audit
+    created_at TIMESTAMPTZ DEFAULT NOW() NOT NULL,
+    updated_at TIMESTAMPTZ DEFAULT NOW() NOT NULL,
+    created_by UUID REFERENCES users.users(id) ON DELETE SET NULL,
+    deleted_at TIMESTAMPTZ,
+
+    -- Constraints
+    CONSTRAINT check_close_status CHECK (
+        (won_at IS NULL OR lost_at IS NULL) -- Cannot be both won and lost
+    )
+);
+
+COMMENT ON TABLE sales.opportunities IS 'Sales opportunities/deals';
+COMMENT ON COLUMN sales.opportunities.probability IS 'Win probability percentage (0-100)';
+
+-- ============================================
+-- Activities (calls, meetings, tasks, etc.)
+-- ============================================
+CREATE TABLE sales.activities (
+    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    tenant_id UUID NOT NULL REFERENCES tenants.tenants(id) ON DELETE CASCADE,
+
+    -- Activity type
+    type sales.activity_type NOT NULL,
+    status sales.activity_status DEFAULT 'pending' NOT NULL,
+
+    -- Content
+    subject VARCHAR(255) NOT NULL,
+    description TEXT,
+
+    -- Related records (at least one should be set)
+    lead_id UUID REFERENCES sales.leads(id) ON DELETE CASCADE,
+    opportunity_id UUID REFERENCES sales.opportunities(id) ON DELETE CASCADE,
+
+    -- Scheduling
+    due_date TIMESTAMPTZ,
+    due_time TIME,
+    duration_minutes INT,
+
+    -- Completion
+    completed_at TIMESTAMPTZ,
+    outcome TEXT,
+
+    -- Assignment
+    assigned_to UUID REFERENCES users.users(id) ON DELETE SET NULL,
+    created_by UUID REFERENCES users.users(id) ON DELETE SET NULL,
+
+    -- For calls
+    call_direction VARCHAR(10), -- 'inbound' or 'outbound'
+    call_recording_url VARCHAR(500),
+
+    -- For meetings
+    location VARCHAR(255),
+    meeting_url VARCHAR(500),
+    attendees JSONB DEFAULT '[]'::jsonb,
+
+    -- Reminder
+    reminder_at TIMESTAMPTZ,
+    reminder_sent BOOLEAN DEFAULT FALSE,
+
+    -- Custom fields
+    custom_fields JSONB DEFAULT '{}'::jsonb,
+
+    -- Audit
+    created_at TIMESTAMPTZ DEFAULT NOW() NOT NULL,
+    updated_at TIMESTAMPTZ DEFAULT NOW() NOT NULL,
+    deleted_at TIMESTAMPTZ,
+
+    -- Constraints
+    CONSTRAINT check_related_record CHECK (
+        lead_id IS NOT NULL OR opportunity_id IS NOT NULL
+    )
+);
+
+COMMENT ON TABLE sales.activities IS 'Sales activities: calls, meetings, tasks, emails, notes';
+COMMENT ON COLUMN sales.activities.attendees IS 'JSON array of meeting attendees';
+
+-- ============================================
+-- Triggers for updated_at
+-- ============================================
+CREATE OR REPLACE FUNCTION sales.update_updated_at()
+RETURNS TRIGGER AS $$
+BEGIN
+    NEW.updated_at = NOW();
+    RETURN NEW;
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE TRIGGER trg_pipeline_stages_updated_at
+    BEFORE UPDATE ON sales.pipeline_stages
+    FOR EACH ROW
+    EXECUTE FUNCTION sales.update_updated_at();
+
+CREATE TRIGGER trg_leads_updated_at
+    BEFORE UPDATE ON sales.leads
+    FOR EACH ROW
+    EXECUTE FUNCTION sales.update_updated_at();
+
+CREATE TRIGGER trg_opportunities_updated_at
+    BEFORE UPDATE ON sales.opportunities
+    FOR EACH ROW
+    EXECUTE FUNCTION sales.update_updated_at();
+
+CREATE TRIGGER trg_activities_updated_at
+    BEFORE UPDATE ON sales.activities
+    FOR EACH ROW
+    EXECUTE FUNCTION sales.update_updated_at();
diff --git a/ddl/schemas/sales/03-functions.sql b/ddl/schemas/sales/03-functions.sql
new file mode 100644
index 0000000..108c16a
--- /dev/null
+++ b/ddl/schemas/sales/03-functions.sql
@@ -0,0 +1,252 @@
+-- ============================================
+-- TEMPLATE-SAAS: Sales Functions
+-- Version: 1.0.0
+-- Module: SAAS-018
+-- ============================================
+
+-- ============================================
+-- Function: Convert Lead to Opportunity
+-- ============================================
+CREATE OR REPLACE FUNCTION sales.convert_lead_to_opportunity(
+    p_lead_id UUID,
+    p_opportunity_name VARCHAR(255) DEFAULT NULL,
+    p_amount DECIMAL(15, 2) DEFAULT 0,
+    p_expected_close_date DATE DEFAULT NULL
+)
+RETURNS UUID AS $$
+DECLARE
+    v_lead RECORD;
+    v_opportunity_id UUID;
+    v_tenant_id UUID;
+BEGIN
+    -- Get lead data
+    SELECT * INTO v_lead
+    FROM sales.leads
+    WHERE id = p_lead_id
+      AND deleted_at IS NULL
+      AND status != 'converted';
+
+    IF NOT FOUND THEN
+        RAISE EXCEPTION 'Lead not found or already converted';
+    END IF;
+
+    v_tenant_id := v_lead.tenant_id;
+
+    -- Create opportunity
+    INSERT INTO sales.opportunities (
+        tenant_id,
+        name,
+        lead_id,
+        stage,
+        amount,
+        currency,
+        expected_close_date,
+        assigned_to,
+        contact_name,
+        contact_email,
+        contact_phone,
+        company_name,
+        notes,
+        created_by
+    ) VALUES (
+        v_tenant_id,
+        COALESCE(p_opportunity_name, v_lead.company || ' - ' || v_lead.first_name || ' ' || v_lead.last_name),
+        p_lead_id,
+        'prospecting',
+        COALESCE(p_amount, 0),
+        'USD',
+        COALESCE(p_expected_close_date, CURRENT_DATE + INTERVAL '30 days'),
+        v_lead.assigned_to,
+        v_lead.first_name || ' ' || v_lead.last_name,
+        v_lead.email,
+        v_lead.phone,
+        v_lead.company,
+        v_lead.notes,
+        v_lead.created_by
+    )
+    RETURNING id INTO v_opportunity_id;
+
+    -- Update lead as converted
+    UPDATE sales.leads
+    SET status = 'converted',
+        converted_at = NOW(),
+        converted_to_opportunity_id = v_opportunity_id
+    WHERE id = p_lead_id;
+
+    RETURN v_opportunity_id;
+END;
+$$ LANGUAGE plpgsql;
+
+COMMENT ON FUNCTION sales.convert_lead_to_opportunity IS 'Converts a lead to an opportunity, copying relevant data';
+
+-- ============================================
+-- Function: Update Opportunity Stage
+-- ============================================
+CREATE OR REPLACE FUNCTION sales.update_opportunity_stage(
+    p_opportunity_id UUID,
+    p_new_stage sales.opportunity_stage,
+    p_notes TEXT DEFAULT NULL
+)
+RETURNS BOOLEAN AS $$
+DECLARE
+    v_opportunity RECORD;
+BEGIN
+    -- Get current opportunity
+    SELECT * INTO v_opportunity
+    FROM sales.opportunities
+    WHERE id = p_opportunity_id
+      AND deleted_at IS NULL;
+
+    IF NOT FOUND THEN
+        RAISE EXCEPTION 'Opportunity not found';
+    END IF;
+
+    -- Update stage
+    UPDATE sales.opportunities
+    SET stage = p_new_stage,
+        notes = CASE
+            WHEN p_notes IS NOT NULL THEN COALESCE(notes, '') || E'\n\n[Stage Change] ' || p_notes
+            ELSE notes
+        END,
+        won_at = CASE WHEN p_new_stage = 'closed_won' THEN NOW() ELSE won_at END,
+        lost_at = CASE WHEN p_new_stage = 'closed_lost' THEN NOW() ELSE lost_at END,
+        actual_close_date = CASE
+            WHEN p_new_stage IN ('closed_won', 'closed_lost') THEN CURRENT_DATE
+            ELSE actual_close_date
+        END
+    WHERE id = p_opportunity_id;
+
+    RETURN TRUE;
+END;
+$$ LANGUAGE plpgsql;
+
+COMMENT ON FUNCTION sales.update_opportunity_stage IS 'Updates opportunity stage with automatic win/loss tracking';
+
+-- ============================================
+-- Function: Calculate Lead Score
+-- ============================================
+CREATE OR REPLACE FUNCTION sales.calculate_lead_score(
+    p_lead_id UUID
+)
+RETURNS INT AS $$
+DECLARE
+    v_lead RECORD;
+    v_score INT := 0;
+    v_activity_count INT;
+BEGIN
+    -- Get lead data
+    SELECT * INTO v_lead
+    FROM sales.leads
+    WHERE id = p_lead_id
+      AND deleted_at IS NULL;
+
+    IF NOT FOUND THEN
+        RETURN 0;
+    END IF;
+
+    -- Base score for having email
+    IF v_lead.email IS NOT NULL THEN
+        v_score := v_score + 10;
+    END IF;
+
+    -- Score for phone
+    IF v_lead.phone IS NOT NULL THEN
+        v_score := v_score + 10;
+    END IF;
+
+    -- Score for company
+    IF v_lead.company IS NOT NULL THEN
+        v_score := v_score + 15;
+    END IF;
+
+    -- Score based on source
+    CASE v_lead.source
+        WHEN 'referral' THEN v_score := v_score + 20;
+        WHEN 'website' THEN v_score := v_score + 15;
+        WHEN 'event' THEN v_score := v_score + 10;
+        ELSE v_score := v_score + 5;
+    END CASE;
+
+    -- Score based on status
+    CASE v_lead.status
+        WHEN 'qualified' THEN v_score := v_score + 25;
+        WHEN 'contacted' THEN v_score := v_score + 15;
+        WHEN 'new' THEN v_score := v_score + 5;
+        ELSE NULL;
+    END CASE;
+
+    -- Score for activities
+    SELECT COUNT(*) INTO v_activity_count
+    FROM sales.activities
+    WHERE lead_id = p_lead_id
+      AND deleted_at IS NULL;
+
+    v_score := v_score + LEAST(v_activity_count * 5, 20);
+
+    -- Cap at 100
+    RETURN LEAST(v_score, 100);
+END;
+$$ LANGUAGE plpgsql;
+
+COMMENT ON FUNCTION sales.calculate_lead_score IS 'Calculates a lead score based on completeness and engagement';
+
+-- ============================================
+-- Function: Get Pipeline Summary
+-- ============================================
+CREATE OR REPLACE FUNCTION sales.get_pipeline_summary(
+    p_tenant_id UUID
+)
+RETURNS TABLE (
+    stage sales.opportunity_stage,
+    count BIGINT,
+    total_amount DECIMAL(15, 2),
+    avg_probability NUMERIC
+) AS $$
+BEGIN
+    RETURN QUERY
+    SELECT
+        o.stage,
+        COUNT(*)::BIGINT,
+        COALESCE(SUM(o.amount), 0)::DECIMAL(15, 2),
+        COALESCE(AVG(o.probability), 0)::NUMERIC
+    FROM sales.opportunities o
+    WHERE o.tenant_id = p_tenant_id
+      AND o.deleted_at IS NULL
+    GROUP BY o.stage
+    ORDER BY
+        CASE o.stage
+            WHEN 'prospecting' THEN 1
+            WHEN 'qualification' THEN 2
+            WHEN 'proposal' THEN 3
+            WHEN 'negotiation' THEN 4
+            WHEN 'closed_won' THEN 5
+            WHEN 'closed_lost' THEN 6
+        END;
+END;
+$$ LANGUAGE plpgsql;
+
+COMMENT ON FUNCTION sales.get_pipeline_summary IS 'Returns summary of opportunities by stage for a tenant';
+
+-- ============================================
+-- Function: Initialize Default Pipeline Stages
+-- ============================================
+CREATE OR REPLACE FUNCTION sales.initialize_default_stages(
+    p_tenant_id UUID
+)
+RETURNS VOID AS $$
+BEGIN
+    -- Insert default stages if none exist
+    IF NOT EXISTS (SELECT 1 FROM sales.pipeline_stages WHERE tenant_id = p_tenant_id) THEN
+        INSERT INTO sales.pipeline_stages (tenant_id, name, position, color, is_won, is_lost)
+        VALUES
+            (p_tenant_id, 'Prospecting', 1, '#94A3B8', FALSE, FALSE),
+            (p_tenant_id, 'Qualification', 2, '#3B82F6', FALSE, FALSE),
+            (p_tenant_id, 'Proposal', 3, '#8B5CF6', FALSE, FALSE),
+            (p_tenant_id, 'Negotiation', 4, '#F59E0B', FALSE, FALSE),
+            (p_tenant_id, 'Closed Won', 5, '#10B981', TRUE, FALSE),
+            (p_tenant_id, 'Closed Lost', 6, '#EF4444', FALSE, TRUE);
+    END IF;
+END;
+$$ LANGUAGE plpgsql;
+
+COMMENT ON FUNCTION sales.initialize_default_stages IS 'Creates default pipeline stages for a new tenant';
diff --git a/ddl/schemas/sales/04-rls.sql b/ddl/schemas/sales/04-rls.sql
new file mode 100644
index 0000000..8c85053
--- /dev/null
+++ b/ddl/schemas/sales/04-rls.sql
@@ -0,0 +1,111 @@
+-- ============================================
+-- TEMPLATE-SAAS: Sales Row Level Security
+-- Version: 1.0.0
+-- Module: SAAS-018
+-- ============================================
+
+-- ============================================
+-- Enable RLS on all tables
+-- ============================================
+ALTER TABLE sales.pipeline_stages ENABLE ROW LEVEL SECURITY;
+ALTER TABLE sales.leads ENABLE ROW LEVEL SECURITY;
+ALTER TABLE sales.opportunities ENABLE ROW LEVEL SECURITY;
+ALTER TABLE sales.activities ENABLE ROW LEVEL SECURITY;
+
+-- ============================================
+-- Pipeline Stages Policies
+-- ============================================
+CREATE POLICY pipeline_stages_tenant_isolation ON sales.pipeline_stages
+    USING (tenant_id = current_setting('app.current_tenant_id', true)::UUID);
+
+CREATE POLICY pipeline_stages_insert ON sales.pipeline_stages
+    FOR INSERT
+    WITH CHECK (tenant_id = current_setting('app.current_tenant_id', true)::UUID);
+
+CREATE POLICY pipeline_stages_update ON sales.pipeline_stages
+    FOR UPDATE
+    USING (tenant_id = current_setting('app.current_tenant_id', true)::UUID);
+
+CREATE POLICY pipeline_stages_delete ON sales.pipeline_stages
+    FOR DELETE
+    USING (tenant_id = current_setting('app.current_tenant_id', true)::UUID);
+
+-- ============================================
+-- Leads Policies
+-- ============================================
+CREATE POLICY leads_tenant_isolation ON sales.leads
+    USING (tenant_id = current_setting('app.current_tenant_id', true)::UUID);
+
+CREATE POLICY leads_insert ON sales.leads
+    FOR INSERT
+    WITH CHECK (tenant_id = current_setting('app.current_tenant_id', true)::UUID);
+
+CREATE POLICY leads_update ON sales.leads
+    FOR UPDATE
+    USING (tenant_id = current_setting('app.current_tenant_id', true)::UUID);
+
+CREATE POLICY leads_delete ON sales.leads
+    FOR DELETE
+    USING (tenant_id = current_setting('app.current_tenant_id', true)::UUID);
+
+-- ============================================
+-- Opportunities Policies
+-- ============================================
+CREATE POLICY opportunities_tenant_isolation ON sales.opportunities
+    USING (tenant_id = current_setting('app.current_tenant_id', true)::UUID);
+
+CREATE POLICY opportunities_insert ON sales.opportunities
+    FOR INSERT
+    WITH CHECK (tenant_id = current_setting('app.current_tenant_id', true)::UUID);
+
+CREATE POLICY opportunities_update ON sales.opportunities
+    FOR UPDATE
+    USING (tenant_id = current_setting('app.current_tenant_id', true)::UUID);
+
+CREATE POLICY opportunities_delete ON sales.opportunities
+    FOR DELETE
+    USING (tenant_id = current_setting('app.current_tenant_id', true)::UUID);
+
+-- ============================================
+-- Activities Policies
+-- ============================================
+CREATE POLICY activities_tenant_isolation ON sales.activities
+    USING (tenant_id = current_setting('app.current_tenant_id', true)::UUID);
+
+CREATE POLICY activities_insert ON sales.activities
+    FOR INSERT
+    WITH CHECK (tenant_id = current_setting('app.current_tenant_id', true)::UUID);
+
+CREATE POLICY activities_update ON sales.activities
+    FOR UPDATE
+    USING (tenant_id = current_setting('app.current_tenant_id', true)::UUID);
+
+CREATE POLICY activities_delete ON sales.activities
+    FOR DELETE
+    USING (tenant_id = current_setting('app.current_tenant_id', true)::UUID);
+
+-- ============================================
+-- Bypass policies for service role (optional)
+-- ============================================
+-- These allow backend services with elevated privileges to bypass RLS
+-- when needed (e.g., for admin operations, reporting, etc.)
+
+-- CREATE POLICY pipeline_stages_service_bypass ON sales.pipeline_stages
+--     FOR ALL
+--     TO template_saas_service
+--     USING (true);
+
+-- CREATE POLICY leads_service_bypass ON sales.leads
+--     FOR ALL
+--     TO template_saas_service
+--     USING (true);
+
+-- CREATE POLICY opportunities_service_bypass ON sales.opportunities
+--     FOR ALL
+--     TO template_saas_service
+--     USING (true);
+
+-- CREATE POLICY activities_service_bypass ON sales.activities
+--     FOR ALL
+--     TO template_saas_service
+--     USING (true);
diff --git a/ddl/schemas/sales/05-indexes.sql b/ddl/schemas/sales/05-indexes.sql
new file mode 100644
index 0000000..deabeb9
--- /dev/null
+++ b/ddl/schemas/sales/05-indexes.sql
@@ -0,0 +1,120 @@
+-- ============================================
+-- TEMPLATE-SAAS: Sales Indexes
+-- Version: 1.0.0
+-- Module: SAAS-018
+-- ============================================
+
+-- ============================================
+-- Pipeline Stages Indexes
+-- ============================================
+CREATE INDEX idx_pipeline_stages_tenant ON sales.pipeline_stages(tenant_id);
+CREATE INDEX idx_pipeline_stages_position ON sales.pipeline_stages(tenant_id, position);
+CREATE INDEX idx_pipeline_stages_active ON sales.pipeline_stages(tenant_id, is_active) WHERE is_active = TRUE;
+
+-- ============================================
+-- Leads Indexes
+-- ============================================
+-- Primary indexes
+CREATE INDEX idx_leads_tenant ON sales.leads(tenant_id);
+CREATE INDEX idx_leads_status ON sales.leads(tenant_id, status);
+CREATE INDEX idx_leads_source ON sales.leads(tenant_id, source);
+CREATE INDEX idx_leads_assigned ON sales.leads(assigned_to) WHERE assigned_to IS NOT NULL;
+
+-- Search indexes
+CREATE INDEX idx_leads_email ON sales.leads(tenant_id, email) WHERE email IS NOT NULL;
+CREATE INDEX idx_leads_company ON sales.leads(tenant_id, company) WHERE company IS NOT NULL;
+
+-- Full-text search on name
+CREATE INDEX idx_leads_name_search ON sales.leads
+    USING gin(to_tsvector('simple', first_name || ' ' || last_name));
+
+-- Score for prioritization
+CREATE INDEX idx_leads_score ON sales.leads(tenant_id, score DESC) WHERE deleted_at IS NULL;
+
+-- Soft delete filter
+CREATE INDEX idx_leads_active ON sales.leads(tenant_id)
+    WHERE deleted_at IS NULL;
+
+-- Conversion tracking
+CREATE INDEX idx_leads_converted ON sales.leads(tenant_id, converted_at)
+    WHERE converted_at IS NOT NULL;
+
+-- ============================================
+-- Opportunities Indexes
+-- ============================================
+-- Primary indexes
+CREATE INDEX idx_opportunities_tenant ON sales.opportunities(tenant_id);
+CREATE INDEX idx_opportunities_stage ON sales.opportunities(tenant_id, stage);
+CREATE INDEX idx_opportunities_stage_id ON sales.opportunities(tenant_id, stage_id) WHERE stage_id IS NOT NULL;
+CREATE INDEX idx_opportunities_assigned ON sales.opportunities(assigned_to) WHERE assigned_to IS NOT NULL;
+
+-- Value-based queries
+CREATE INDEX idx_opportunities_amount ON sales.opportunities(tenant_id, amount DESC);
+CREATE INDEX idx_opportunities_probability ON sales.opportunities(tenant_id, probability DESC);
+
+-- Date-based queries
+CREATE INDEX idx_opportunities_expected_close ON sales.opportunities(tenant_id, expected_close_date);
+CREATE INDEX idx_opportunities_won ON sales.opportunities(tenant_id, won_at) WHERE won_at IS NOT NULL;
+CREATE INDEX idx_opportunities_lost ON sales.opportunities(tenant_id, lost_at) WHERE lost_at IS NOT NULL;
+
+-- Lead reference
+CREATE INDEX idx_opportunities_lead ON sales.opportunities(lead_id) WHERE lead_id IS NOT NULL;
+
+-- Soft delete filter
+CREATE INDEX idx_opportunities_active ON sales.opportunities(tenant_id)
+    WHERE deleted_at IS NULL;
+
+-- Pipeline view (common query pattern)
+CREATE INDEX idx_opportunities_pipeline ON sales.opportunities(tenant_id, stage, amount DESC)
+    WHERE deleted_at IS NULL AND won_at IS NULL AND lost_at IS NULL;
+
+-- ============================================
+-- Activities Indexes
+-- ============================================
+-- Primary indexes
+CREATE INDEX idx_activities_tenant ON sales.activities(tenant_id);
+CREATE INDEX idx_activities_type ON sales.activities(tenant_id, type);
+CREATE INDEX idx_activities_status ON sales.activities(tenant_id, status);
+
+-- Related records
+CREATE INDEX idx_activities_lead ON sales.activities(lead_id) WHERE lead_id IS NOT NULL;
+CREATE INDEX idx_activities_opportunity ON sales.activities(opportunity_id) WHERE opportunity_id IS NOT NULL;
+
+-- Assignment
+CREATE INDEX idx_activities_assigned ON sales.activities(assigned_to) WHERE assigned_to IS NOT NULL;
+
+-- Scheduling
+CREATE INDEX idx_activities_due_date ON sales.activities(tenant_id, due_date)
+    WHERE status = 'pending' AND deleted_at IS NULL;
+
+-- Upcoming activities (common query)
+CREATE INDEX idx_activities_upcoming ON sales.activities(tenant_id, due_date, type)
+    WHERE status = 'pending' AND deleted_at IS NULL AND due_date IS NOT NULL;
+
+-- Reminders
+CREATE INDEX idx_activities_reminder ON sales.activities(reminder_at)
+    WHERE reminder_sent = FALSE AND reminder_at IS NOT NULL AND status = 'pending';
+
+-- Soft delete filter
+CREATE INDEX idx_activities_active ON sales.activities(tenant_id)
+    WHERE deleted_at IS NULL;
+
+-- ============================================
+-- Composite indexes for common queries
+-- ============================================
+
+-- Dashboard: leads by status with score
+CREATE INDEX idx_leads_dashboard ON sales.leads(tenant_id, status, score DESC)
+    WHERE deleted_at IS NULL;
+
+-- Dashboard: opportunities pipeline
+CREATE INDEX idx_opportunities_dashboard ON sales.opportunities(tenant_id, stage, expected_close_date)
+    WHERE deleted_at IS NULL AND won_at IS NULL AND lost_at IS NULL;
+
+-- Activity feed for a lead
+CREATE INDEX idx_activities_lead_feed ON sales.activities(lead_id, created_at DESC)
+    WHERE deleted_at IS NULL;
+
+-- Activity feed for an opportunity
+CREATE INDEX idx_activities_opportunity_feed ON sales.activities(opportunity_id, created_at DESC)
+    WHERE deleted_at IS NULL;