The Customs Department has warned the Government it may not have enough funding to meet increased growth in trade and travel.
The department was forecasting another 1.4 million international travellers during the next four years, and the value of trade to jump by $16.3 billion in the same period.
Customs was allocated nearly $160 million a year for the next three years, but in a briefing to the Minister Nicky Wagner, it said that may not be sufficient.
However, Ms Wagner said Government departments always wanted more money.
"I think Government departments always want more money and our Government has been pretty focused on making sure that we spend tax payers money as carefully as possible."
She said Customs would continue to be creative and work hard within its baseline funding.
The Public Service Association also said there would be more problems at the border if the Government did not give the Customs Department more money.
PSA National Secretary Richard Wagstaff said that asking the department to do more with less money was unrealistic.
"There are some things creativity just won't patch up and we can't pay fast and loose with things like Customs.
"The Government really needs to get its head out of the sand if it just thinks we can keep doing more with less, that's not going top happen, there are just going to be more problems."
Mr Wagstaff said Customs officers were also well overdue for a pay rise.