The website is one of Ireland's most popular with 3.3m visitors last month.
It was acquired by the Irish Times Group earlier this year as part of the expansion of its digital services.
In a statement, RIP.ie said it believed the new fee structure offers "fair and good value for money" and would support the development and enhancement of the RIP.ie service.
"We have no plans to introduce a charge to users of the site. RIP.ie remains committed to offering an excellent service and a secure platform where bereaved families can be supported in commemorating their loved ones.”
A €100 fee is already in place for death notices for a funeral taking place abroad.
The website also charges fees for death acknowledgements, anniversaries and month's minds and sells memorial gifts.
“Investing in our service will ensure that RIP.ie remains a trusted resource for bereaved families across Ireland and for the hundreds of thousands of people who post messages of condolence to bereaved families on the site every week," the company said.