Oh yes, I do this all the time with credit card info and I have not (yet) had a problem.
One time they were having a problem with one card, and they actually emailed me.
I normally ask for a few records at a time, and so I just send them my own reusable letter with my credit card info in them, with the items out Irish Civil Registration copied and pasted in and formatted. I also include a contact email.
So far my credit card is in far greater danger at the mall. Two years ago, after shopping for a gift for my Irish aunt at the mall a few weeks before leaving for Ireland, I arrived home about an hour later only to discover emails and a phone message from Bank of America alerting me to suspicious activity and notification the bank had locked down my account. Somebody at the store where I shopped helped themselves to my number, apparently, and quickly ran up a big charge on it.