The Department of Foreign Affairs paid out nearly €30m in allowances to staff in the space of 18 months.
More than 21 different payment categories are available including allowances for footwear, key holding, unsocial hours, driving, overseas service, and caring for children abroad.
Allowance payments in 2024 totalled €19.1m with a further €10.8m paid out during the first six months of this year.
Department figures show that €15m of the €29.8m total went on what are known as local post allowances.
These are payments made to cover the "additional indirect costs" involved in the representational role of diplomatic staff.
The department said the allowance varies according to marital status and seniority and is payable at all locations abroad.
In addition, the expenditure included payments for "hardship" posts where staff get extra cash for serving in more challenging locations.
This is generally based on distance from Ireland, levels of crime and air pollution, political tension, and access to healthcare.
A further €10.5m was paid out in cost-of-living allowances, which apply in diplomatic postings where daily life is more expensive than Dublin.
An information note said: "The department uses the services of an independent firm to provide cost of living indices for the various locations required. [This allowance] only becomes payable at posts with a higher cost of living index than Dublin."
There was a further €3.22m in payments for children's foreign allowance, records released under FOI show.
These payments are intended to compensate staff for the additional costs incurred in having their kids overseas with them.
A total of €1.1m was paid in other allowances, which includes a lengthy list of entitlements for certain staff.
These included a "Brussels on-call" allowance, a payment for "extra attendance" and allowances for private secretaries to the minister and department secretary general.
Other allowances listed were a "web and digital on-call allowance," one for "unsocial hours night watchman" and another called a "franking allowance."
Asked about the expenditure, a spokesman for the Department of Foreign Affairs said all their staff were paid in line with official pay scales.
"In common with other diplomatic services, this department further supports officers who are assigned abroad to serve the state in an official capacity through a system of Foreign Service Allowances," he said.
"This is to assist in defraying the additional costs to officers and their families of moving and living abroad. Allowances are based on independently sourced data," he added.
Reporting by Ken Foxe
