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

Complete
Ireland → Peer, Limburg, Belgium
Item Name Destination Amount Conditions
Meal & Lodging Brussels, Belgium 241.5 EUR per night Overnight rate covering accommodation and three meals for a 24-hour absence abroad on official business.; Brussels: the vouched cost of room plus the VA rate is applicable to all officers travelling to Brussels on overnight visits (Note 2, Circular 07/2017).
Vouched Accommodation (VA) Rate Brussels, Belgium 120.75 EUR 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 Brussels, Belgium 80.5 EUR per day Ten-hour rate: applies to an absence abroad of ten hours or more without an overnight stay.
Daily allowance Brussels, Belgium 40.25 EUR per day Five-hour rate: applies to an absence abroad of between five and ten hours.

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.