I am starting work this year. Is there a minimum number of months that I have to start working for before I am eligible to apply for credit cards?

Technically you can start applying for CC once you are employed. But I realised that most banks require 3 months of payslip. So perhaps it would be good for you to wait till about 3 to 4 months.

I think it depends on your credit history and also depends on the banks. Some banks are easier to apply and get approval, some are more stringent.

Technically, you can start applying for the Credit Card immediately once you gained employment. With your employment contract, it will state you monthly salary and the bank will use that amount x 12 to figure out your annual salary.

If you have no credit history at all, it may be abit hard for you to get approval for a start. If the banks are lenient, maybe they will give you an approval with lower limit. However, if you keep getting rejected due to immature credit history, I suggest you to wait for your income tax (1 year after employment).

Note: NEVER EVER SPAM YOUR CC APPLICATIONS. Do not apply for multiple credit facilities from different banks in a short duration. Every application have a record, even if its rejected. If you keep spamming, it may make you look bad and affect your credit score.

For myself, I started building my credit score since 18 with a student credit card (Maybank eVibes 1% Cashback). I have also applied for Secured Credit Card to get higher cashbacks (UOB One with $10,000 FD). Till date, I've perfected my credit score of 2000 (AA).