The Greenock Telegraph reported that the first batch of jobs will go in November, with others to follow in March.
The bank launched a voluntary redundancy programme earlier this year, with the aim of reducing headcount across its three mortgage centres by 150.
A spokesperson for RBS told Mortgage Solutions: “We have been able to achieve all of our headcount reduction across the three sites through voluntary redundancies and were oversubscribed for the register in Greenock.”
It was reported that the jobs were being cut as a result of increased internet banking and online mortgage applications.
Full-time and part-time staff are being affected by the changes.