diff --git a/drcr/models.py b/drcr/models.py
index 2494387..7c6390b 100644
--- a/drcr/models.py
+++ b/drcr/models.py
@@ -129,6 +129,10 @@ class TrialBalancer:
 		
 		# TODO: Keep a record of internal transactions?
 		
+		if source_account == destination_account:
+			# Don't do anything in this case!!
+			return
+		
 		if source_account not in self.accounts:
 			return
 		
diff --git a/drcr/reports/views.py b/drcr/reports/views.py
index 331cd5c..d42e2bc 100644
--- a/drcr/reports/views.py
+++ b/drcr/reports/views.py
@@ -16,13 +16,12 @@
 
 from flask import render_template
 
-from ..config import BALANCE_SHEET_MAPPING, COA_MAPPING
+from ..config import BALANCE_SHEET_MAPPING, COA_MAPPING, INCOME_STATEMENT_MAPPING
 from ..models import Amount, TrialBalancer
 from ..webapp import all_transactions, app
 
-@app.route('/reports/balance-sheet')
-def balance_sheet():
-	# Extract trial balance
+def get_trial_balance():
+	# Get trial balance and validate COA
 	balancer = TrialBalancer()
 	balancer.apply_transactions(all_transactions())
 	
@@ -30,7 +29,50 @@ def balance_sheet():
 	for source_account, destination_account in COA_MAPPING.items():
 		balancer.transfer_balance(source_account, destination_account)
 	
-	balancer.transfer_balance('Income', 'Current year surplus (deficit)')
-	balancer.transfer_balance('Expenses', 'Current year surplus (deficit)')
+	return balancer
+	
+	# Validate COA
+	for account in balancer.accounts:
+		if account in BALANCE_SHEET_MAPPING['Current assets']:
+			continue
+		if account in BALANCE_SHEET_MAPPING['Non-current assets']:
+			continue
+		if account in BALANCE_SHEET_MAPPING['Current liabilities']:
+			continue
+		if account in BALANCE_SHEET_MAPPING['Non-current liabilities']:
+			continue
+		if account in INCOME_STATEMENT_MAPPING['Income']:
+			continue
+		if account in INCOME_STATEMENT_MAPPING['Expenses']:
+			continue
+		if account == 'Accumulated surplus (deficit)':
+			continue
+		
+		raise Exception('Account "{}" is not mapped to a report'.format(account))
+	
+	return balancer
+
+#@app.route('/reports/mapped-trial-balance')
+#def mapped_trial_balance():
+#	balancer = get_trial_balance()
+#	
+#	total_dr = Amount(sum(v.quantity for v in balancer.accounts.values() if v.quantity > 0), '$')
+#	total_cr = Amount(sum(v.quantity for v in balancer.accounts.values() if v.quantity < 0), '$')
+#	
+#	return render_template('trial_balance.html', accounts=dict(sorted(balancer.accounts.items())), total_dr=total_dr, total_cr=total_cr)
+
+@app.route('/reports/balance-sheet')
+def balance_sheet():
+	balancer = get_trial_balance()
+	
+	# Transfer surplus to balance sheet
+	for account in INCOME_STATEMENT_MAPPING['Income'] + INCOME_STATEMENT_MAPPING['Expenses']:
+		balancer.transfer_balance(account, 'Current year surplus (deficit)')
 	
 	return render_template('reports/balance_sheet.html', accounts=balancer.accounts, running_total=Amount(0, '$'), BALANCE_SHEET_MAPPING=BALANCE_SHEET_MAPPING)
+
+@app.route('/reports/income-statement')
+def income_statement():
+	balancer = get_trial_balance()
+	
+	return render_template('reports/income_statement.html', accounts=balancer.accounts, running_total=Amount(0, '$'), INCOME_STATEMENT_MAPPING=INCOME_STATEMENT_MAPPING)
diff --git a/drcr/templates/index.html b/drcr/templates/index.html
index b831fcc..f475053 100644
--- a/drcr/templates/index.html
+++ b/drcr/templates/index.html
@@ -35,5 +35,6 @@
 	<h1 class="h2 my-4">Advanced reports</h1>
 	<ul>
 		<li><a href="/reports/balance-sheet">Balance sheet</a></li>
+		<li><a href="/reports/income-statement">Income statement</a></li>
 	</ul>
 {% endblock %}
diff --git a/drcr/templates/reports/balance_sheet.html b/drcr/templates/reports/balance_sheet.html
index 003dc28..f4a5e1f 100644
--- a/drcr/templates/reports/balance_sheet.html
+++ b/drcr/templates/reports/balance_sheet.html
@@ -29,7 +29,11 @@
 
 {% macro acctrow(name, mul=1) %}
 	<tr>
-		<td>{{ name }}</td>
+		{% if name == 'Current year surplus (deficit)' %}
+			<td><a href="/reports/income-statement">{{ name }}</a></td>
+		{% else %}
+			<td>{{ name }}</td>
+		{% endif %}
 		<td class="text-end">{{ fmtbal(accounts[name], mul) }}</td>
 	</tr>
 	{% set _ = running_total.__setattr__('quantity', running_total.quantity + accounts[name].quantity) %}
@@ -42,7 +46,7 @@
 		<thead>
 			<tr style="border-width:0 0 1px 0">
 				<th></th>
-				<th class="text-end">$</th>
+				<th class="text-end">$&nbsp;</th>
 			</tr>
 		</thead>
 		<tbody>
diff --git a/drcr/templates/reports/income_statement.html b/drcr/templates/reports/income_statement.html
new file mode 100644
index 0000000..76bf50a
--- /dev/null
+++ b/drcr/templates/reports/income_statement.html
@@ -0,0 +1,86 @@
+{#  DrCr: Web-based double-entry bookkeeping framework
+    Copyright (C) 2022  Lee Yingtong Li (RunasSudo)
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+#}
+
+{% extends 'base.html' %}
+{% block title %}Income statement{% endblock %}
+
+{% macro fmtbal(amount, mul=1) %}
+	{# FIXME: Honour AMOUNT_DPS #}
+	{% if amount.quantity * mul >= 0 %}
+		{{ '{:,.2f}'.format(amount.quantity|abs / 100) }}&nbsp;
+	{% else %}
+		({{ '{:,.2f}'.format(amount.quantity|abs / 100) }})
+	{% endif %}
+{% endmacro %}
+
+{% macro acctrow(name, mul=1) %}
+	<tr>
+		<td>{{ name }}</td>
+		<td class="text-end">{{ fmtbal(accounts[name], mul) }}</td>
+	</tr>
+	{% set _ = running_total.__setattr__('quantity', running_total.quantity + accounts[name].quantity) %}
+{% endmacro %}
+
+{% block content %}
+	<h1 class="h2 mt-4">Income statement</h1>
+	
+	<table class="table table-borderless table-sm">
+		<thead>
+			<tr style="border-width:0 0 1px 0">
+				<th></th>
+				<th class="text-end">$&nbsp;</th>
+			</tr>
+		</thead>
+		<tbody>
+			<tr>
+				<th colspan="2">Income</th>
+			</tr>
+			{% set _ = running_total.__setattr__('quantity', 0) %}
+			{% for account in INCOME_STATEMENT_MAPPING['Income'] if account in accounts %}
+				{{ acctrow(account, -1) }}
+			{% endfor %}
+			<tr>
+				<th>Total income</th>
+				<th class="text-end">{{ fmtbal(running_total, -1) }}</th>
+			</tr>
+			{% set surplus = running_total.quantity %}
+			
+			<tr><td colspan="2">&nbsp;</td></tr>
+			
+			<tr>
+				<th colspan="2">Expenses</th>
+			</tr>
+			{% set _ = running_total.__setattr__('quantity', 0) %}
+			{% for account in INCOME_STATEMENT_MAPPING['Expenses'] if account in accounts %}
+				{{ acctrow(account) }}
+			{% endfor %}
+			<tr>
+				<th>Total expenses</th>
+				<th class="text-end">{{ fmtbal(running_total) }}</th>
+			</tr>
+			{% set surplus = surplus + running_total.quantity %}
+			
+			<tr><td colspan="2">&nbsp;</td></tr>
+			
+			<tr style="border-width:1px 0">
+				<th>Net surplus (deficit)</th>
+				{% set _ = running_total.__setattr__('quantity', surplus) %}
+				<th class="text-end">{{ fmtbal(running_total, -1) }}</th>
+			</tr>
+		</tbody>
+	</table>
+{% endblock %}