Former Junior Minister Ivor Callely has pleaded guilty to fraudulently using an invoice.
He was due to stand trial at the end of the month.
Mr Callely is facing a total of six charges in relation to using bogus invoices, from three phone companies, to claim phone expenses.
He pleaded guilty to using a Business Communication Limited Invoice dated January 2002 as a false instrument on dates between 21 and 22 November at Leinster House, Kildare Street.
Judge Mary Ellen Ring, at Dublin Circuit Criminal Court, set a sentence date of July 22, when full fact will be heard.
Tony McGillicuddy BL, defending, said he expected the sentence hearing to take 40 minutes.
Mr Callely, of St Lawrences Road in Clontarf, had been due to stand later this month after being sent forward from the District Court on charges relating to using invoices as false instruments for receipt of expenses for handsets and equipment, under the Oireachtas members direct purchase mobile phone scheme.
The court heard today's plea does not affect the status of the remaining charges and Mr. Callely was remanded on continuing bail ahead of sentencing