Accounts filed at Companies House show Skibo Limited recorded a dip in turnover from £8.35m to £8m in the 12 months to March 31, 2013, while administrative expenses rose from £7.3m to more than £7.5m.
Writing in the accounts the directors said they were "satisfied with the business performance in the year" and were looking forward to growth in the coming trading year.
Skibo, which covers 7500 acres, has previously hosted the wedding of Madonna to Guy Ritchie and racing driver Dario Franchitti to actress Ashley Judd, as well as being a popular bolt hole for figures ranging from Bill Clinton to Sir Sean Connery.
The accounts were prepared on a going-concern basis, in spite of the company having net liabilities of £538,000.
The accounts said Skibo owner Scytherbolle has indicated it will continue to provide funding and not seek repayment of the money it is owed.
Skibo directors said: "The directors consider that this should enable the company to continue in operational existence for the foreseeable future by meeting its liabilities as they fall due for payment."
A note in the accounts says Scytherbolle, which is based in Bermuda, is owed £14m. Directors' remuneration at Skibo was steady at £232,000 with the highest paid seeing their rewards flat at £126,000.
Overall staff numbers dipped from 179 to 175 but employee costs rose from £3.55m to almost £3.6m.
Net debt edged from £19m from £19.4m while interest repayments went from £800,000 to £804,000.
Although the castle at Dornoch in Sutherland dates back to around the 12th century much of the current site was restored and rebuilt by Dunfermline-born industrial tycoon Andrew Carnegie after he bought the castle in 1898 as a summer home.
Skibo was owned by the Carnegie family until the 1980s and then passed through a number of hands including Lanarkshire businessman Derek Holt, a global real estate investment trust and hotelier Peter de Savary.
In 2003 Mr de Savary sold to a small group of private investors who had been members of Skibo's exclusive Carnegie Club including Sunderland Football Club's American owner Ellis Short.
The value of the deal has never been officially disclosed but is thought to have been around £23m.
There are around 400 members of the Carnegie Club, who each pay an annual fee of around £7690. New members also have to make a one-off £24,000 payment to join.