This follows the same action in August of this year when around 400 staff agreed to take a week's unpaid leave.
In August 2012 the Herald reported that Barnardos said it was operating "to the bone" and felt it had no option but to close temporarily.
The need to carry out the process for the second time is being blamed on repeated cuts to State funding over the past three years as well as a drop in donations to the charity.
Barnardos has already informed staff that it intends to close its services for another week in August 2013 as it looks for ways to cut costs, according to a spokesperson for the charity.
"This cost-cutting measure is to ensure that we can continue to provide vital services to children and families and is in response to increased financial pressure due to repeated cuts to statutory income and a decline in voluntary income," said the spokesperson.
The decision comes following last year's action, which saved the organisation €400,000.
This followed other cut backs such as a reduction in wages and making 14 staff redundant.
The cuts to staff were mainly from the administration sector and remaining staff saw their wages cut by more than 10pc.
The decision will starve customers of all services for one week including phone facilities.
Anyone trying to contact Barnardos will be asked to leave a message or will be given a mobile number to ring in the event of an emergency.
All other queries will be responded to when the organisation returns to normal services. The charity said its decision to close its offices for the second time was not taken lightly and August was chosen as it was the quietest time.
Charity bosses have made repeated calls for more help in the passed year.
In October Barnardos announced that it will cut a literacy programme for disadvantaged children in a bid to keep the organisation afloat.