diff --git a/default_thai_company/hooks.py b/default_thai_company/hooks.py
index a647b72..3be319a 100644
--- a/default_thai_company/hooks.py
+++ b/default_thai_company/hooks.py
@@ -144,6 +144,7 @@ fixtures = [
 after_install = [
 	"default_thai_company.vat.setup_companies",
 	"default_thai_company.shipping.setup_companies",
+	"default_thai_company.payroll.setup_companies",
 ]
 # Fixture import re-inserts the Location tree; restore lft/rgt for user-added nodes.
 after_migrate = "default_thai_company.assets.rebuild_locations"
@@ -160,7 +161,8 @@ after_migrate = "default_thai_company.assets.rebuild_locations"
 # Name of the app being installed is passed as an argument
 
 # before_app_install = "default_thai_company.utils.before_app_install"
-# after_app_install = "default_thai_company.utils.after_app_install"
+# Payroll Period for companies created before hrms was installed.
+after_app_install = "default_thai_company.payroll.after_app_install"
 
 # Integration Cleanup
 # -------------------
@@ -219,6 +221,7 @@ doc_events = {
 			"default_thai_company.vat.setup_company",
 			"default_thai_company.assets.setup_company",
 			"default_thai_company.shipping.setup_company",
+			"default_thai_company.payroll.setup_company",
 		],
 	},
 	"Payment Entry": {
@@ -229,23 +232,10 @@ doc_events = {
 # Scheduled Tasks
 # ---------------
 
-# scheduler_events = {
-# 	"all": [
-# 		"default_thai_company.tasks.all"
-# 	],
-# 	"daily": [
-# 		"default_thai_company.tasks.daily"
-# 	],
-# 	"hourly": [
-# 		"default_thai_company.tasks.hourly"
-# 	],
-# 	"weekly": [
-# 		"default_thai_company.tasks.weekly"
-# 	],
-# 	"monthly": [
-# 		"default_thai_company.tasks.monthly"
-# 	],
-# }
+# Payroll Period is per calendar year; roll the default over on 1 January.
+scheduler_events = {
+	"daily": ["default_thai_company.payroll.setup_companies"],
+}
 
 # Testing
 # -------
diff --git a/default_thai_company/patches.txt b/default_thai_company/patches.txt
index e1ea1ce..5ebeec5 100644
--- a/default_thai_company/patches.txt
+++ b/default_thai_company/patches.txt
@@ -7,3 +7,4 @@
 default_thai_company.patches.create_vat_accounts
 default_thai_company.patches.create_vat_templates
 default_thai_company.patches.create_shipping_rules
+default_thai_company.patches.create_payroll_periods
diff --git a/default_thai_company/patches/create_payroll_periods.py b/default_thai_company/patches/create_payroll_periods.py
new file mode 100644
index 0000000..873a011
--- /dev/null
+++ b/default_thai_company/patches/create_payroll_periods.py
@@ -0,0 +1,5 @@
+from default_thai_company.payroll import setup_companies
+
+
+def execute():
+	setup_companies()
diff --git a/default_thai_company/payroll.py b/default_thai_company/payroll.py
new file mode 100644
index 0000000..e9422fa
--- /dev/null
+++ b/default_thai_company/payroll.py
@@ -0,0 +1,62 @@
+import frappe
+from frappe.utils import getdate
+
+from default_thai_company.tax_withholding import thai_companies
+
+# Thai personal income tax (P.N.D.1/91) is assessed per calendar year whatever
+# the company's fiscal year, so the Payroll Period is January to December.
+# Payroll Period is named by prompt (site-wide unique) but bound to one company,
+# so each Thai company gets "<year> - <abbr>", like the Shipping Rule.
+
+
+def hrms_installed():
+	return "hrms" in frappe.get_installed_apps()
+
+
+def payroll_period_name(company, year):
+	abbr = frappe.get_cached_value("Company", company, "abbr")
+	return f"{year} - {abbr}"
+
+
+def ensure_payroll_period(company, year):
+	"""Calendar-year Payroll Period for `company`. No-op when any period of the
+	company touches the year: an existing one covers it, or the company runs its
+	own scheme and a second period would only fail the overlap check."""
+	start, end = f"{year}-01-01", f"{year}-12-31"
+	if frappe.db.exists(
+		"Payroll Period", {"company": company, "start_date": ("<=", end), "end_date": (">=", start)}
+	):
+		return
+	frappe.get_doc(
+		{
+			"doctype": "Payroll Period",
+			"name": payroll_period_name(company, year),
+			"company": company,
+			"start_date": start,
+			"end_date": end,
+		}
+	).insert(ignore_permissions=True)
+
+
+def setup_company(doc, method=None):
+	"""Company.on_update: this year's Payroll Period for a Thai company."""
+	if doc.country == "Thailand" and hrms_installed():
+		ensure_payroll_period(doc.name, getdate().year)
+
+
+def setup_companies():
+	"""after_install, the daily scheduler, and the create_payroll_periods patch:
+	this year's Payroll Period for every Thai company. The scheduler rolls the
+	default over on 1 January."""
+	if not hrms_installed():
+		return
+	year = getdate().year
+	for company in thai_companies():
+		ensure_payroll_period(company, year)
+
+
+def after_app_install(app_name):
+	"""Payroll Period only exists once hrms is installed; catch companies that
+	were created before it."""
+	if app_name == "hrms":
+		setup_companies()