USI president Will Priestly warned that thousands of students fall into debt soon after the college year begins.
"Credit cards are very handy but we would urge students not to spend large amounts without checking their limit," he said.
Banks and credit companies are offering dozens of student finance packages as the countdown to the beginning of the college term begins.
National Irish Bank's student account offers free banking and an interest-free overdraft where the limit can be agreed with the bank. NIB is offering students loans of up to €7,000 at a rate of 8%.
The Bank of Ireland is willing to give students free banking plus a credit card with a limit of €500.
The bank offers students a loan that's 1.5% lower than the standard rate of interest around 8.5% and a nine month interest-free J1 visa loan.
BoI marketing manager Patrick Farrell said: "The entire student package of products is tailored to tackle cash flow issues while making concessions for the fact that the student does not have the income to support large interest payments.
"With us, cash flow problems can be eased without necessarily getting into debt."
AIB has also redesigned its student package this year and is offering free transactions, a credit card with a €400 limit for online purchases, and a loan that charges interest at 1.5% less than the standard rate. Students can also get an overdraft with interest charged at 9.5%.
A bank spokesperson said: "The AIB student plus account reward scheme gives loyalty rewards to students throughout the year based on the activity on their account. Students who qualify will receive rewards in October and at other times throughout the year."
The cost of living for students is increasing by as much as 30% annually. It can cost a student over €6,000 in maintenance for the nine-month academic year. The basic Government maintenance grant is just €3,264.