I have a website name onlinecheckwriter.com which helps my client to print check online. Right now I'm facing one problem that I didnt find any vendor that provide offical routing never verification api. Right now our customer add routing number but I need cross check it with bank . So I'm looking for a paid api that will give me accurate information I mean bank name from routing number.

Just a note: You appear to be spamming on other forums (CNET in particular.) I'd avoid that in case folk notice that and point out your question here.