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

Complete
Ireland → Spain
Item Name Destination Amount Conditions
Meal & Lodging Barcelona, Spain 277.5 EUR per night Overnight rate covering accommodation and three meals for a 24-hour absence abroad on official business.
Vouched Accommodation (VA) Rate Barcelona, Spain 138.75 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 Barcelona, Spain 92.5 EUR per day Ten-hour rate: applies to an absence abroad of ten hours or more without an overnight stay.
Daily allowance Barcelona, Spain 46.25 EUR per day Five-hour rate: applies to an absence abroad of between five and ten hours.
Meal & Lodging Madrid, Spain 287 EUR per night Overnight rate covering accommodation and three meals for a 24-hour absence abroad on official business.
Vouched Accommodation (VA) Rate Madrid, Spain 143.5 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 Madrid, Spain 95.67 EUR per day Ten-hour rate: applies to an absence abroad of ten hours or more without an overnight stay.
Daily allowance Madrid, Spain 47.83 EUR per day Five-hour rate: applies to an absence abroad of between five and ten hours.
Meal & Lodging All Other, Spain 243.95 EUR per night Overnight rate covering accommodation and three meals for a 24-hour absence abroad on official business.; Applies to locations in Spain other than those separately listed in Appendix 2 of Circular 07/2017.
Vouched Accommodation (VA) Rate All Other, Spain 121.98 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.; Applies to locations in Spain other than those separately listed in Appendix 2 of Circular 07/2017.
Daily allowance All Other, Spain 81.32 EUR per day Ten-hour rate: applies to an absence abroad of ten hours or more without an overnight stay.; Applies to locations in Spain other than those separately listed in Appendix 2 of Circular 07/2017.
Daily allowance All Other, Spain 40.66 EUR per day Five-hour rate: applies to an absence abroad of between five and ten hours.; Applies to locations in Spain 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.