[Specific to Singapore]
Received a mailer from HSBC informing me that now I can pay my income tax using the credit card I have with the bank. "Cool!" was my first impression, since this will mean earning the rewards points for something I will be spending on in the first place.
However, upon reading the brochure in more detail, I realised the procedure is as such:

• make a GIRO arrangement with IRAS to deduct your income tax from a bank account every month
• Send HSBC the GIRO payment plan and the said amount will be paid from the credit card into the said bank account

The interesting thing for me is that the same bank account I will be asking HSBC to credit will the be the same bank account I will be drawing my cheque against to pay HSBC at the end of the month.
Makes little sense for me to sign up for something that will put money in my account just for me to pay them back a few days later. Upside is the rewards points I will get, but the downside will be the interest and penalty I need to incur when I forget to pay my credit card bill in time (which I might, given my absent-mindedness).