Look up per diem reimbursement rates and mileage deductions for business travel worldwide.

Complete
Ireland → TO
Item Name Destination Amount Conditions
Meal & Lodging Nuku'alofa, Tonga 419.5 TOP per night Overnight rate covering accommodation and three meals for a 24-hour absence abroad on official business.
Vouched Accommodation (VA) Rate Nuku'alofa, Tonga 209.75 TOP per night Vouched Accommodation (VA) rate: paid in addition to the vouched cost of accommodation. Per Note 2 of Circular 07/2017 the VA rate should not be routinely used except for travel to Brussels, where the vouched cost of room plus the VA rate applies to all officers on overnight visits.
Daily allowance Nuku'alofa, Tonga 139.83 TOP per day Ten-hour rate: applies to an absence abroad of ten hours or more without an overnight stay.
Daily allowance Nuku'alofa, Tonga 69.92 TOP per day Five-hour rate: applies to an absence abroad of between five and ten hours.
Incidentals All Other, Tonga 10 EUR per day Actual-cost destination (Note 1, Circular 07/2017): the overnight rate is the vouched cost of accommodation and three meals, the ten-hour rate is the vouched cost of two meals and the five-hour rate is the vouched cost of one meal, in each case plus this incidental expenses allowance of EUR 10 per day.; Applies to locations in Tonga other than those separately listed in Appendix 2 of Circular 07/2017.

Source URL:
https://www.revenue.ie/en/employing-people/documents/dper-circular-07-2017-subsistence-allowances-abroad.pdf
This source provides official travel rate information from revenue.ie.