Hi Mike,
I'm certain that most replies to this post will be the same as the majority so far. I've used Epson inks far beyond the "expiration" date with no apparent negative effects. Of course Epson's reply would be totally different, but their job is to sell inks. If you had a problem and called Epson service, the first question would be - "are you using outdated inks?" That's always the lead question, but again, that's the corporate routine. With all of the Epson printers I've owned I have never discarded an "outdated" ink cart and have never regretted it.
Gary