JasonIsaacsonline.com is a completely UNOFFICIAL, nonsanctioned, unacknowledged effort with no direct connection to Jason Isaacs or any of his agents or representatives.  Neither the administrators nor any moderators of the affiliated message board, http://jasonisaacsonline.com/phpBB/index.php, has any way to contact Mr. Isaacs.
     Kids, you're on your own.  When Mr. Isaacs signs up to do a movie, he may be contracted to participate in some publicity activity therefor.  There is no requirement, however, for him to respond in any way to fan mail, which—particularly since the appearance of the Harry Potter franchise—can reach positively epic proportions; as the song has it, Mr. Isaacs is apparently big in Japan.
     That said, Mr. Isaacs has expressed pleasure at receiving fan mail; due to constraints of space and general life accommodation, he probably prefers to get postcards or notes rather than gifts.  If you'd like to write to Mr. Isaacs, the following are the most reliable accurate addresses we have.  Remember that any response is a delightful surprise, not something you should depend upon receiving.  Mr. Isaacs takes his own time to prepare any answers himself.  If you are writing to request a picture, please include a stamped, self-addressed envelope of a size adequate to accommodate a photo. If you write to an address outside your own country, it is considered polite to include IRCs (International Reply Coupons)--these are vouchers which a recipient can take to their own post office to exchange for their local stamps*.  You should be able to get an idea of how much the postage for a large envelope from the U.S. or the UK back to you would be from a local-based website, then purchase an equivalent value in IRCs from your post office for enclosure with your envelope.
    
     The addresses:

     Jason Isaacs  

     Or

      Jason Isaacs  

     In the UK:

     c/o Paul Lyon-Maris
     Independent Talent Group LTD
     Oxford House
     76 Oxford Street
     London, W1D 1BS
     UK

     (The UK agent's office is located in a large, unimpressive building about which Bill Bryson has probably had a good rant, along a somewhat unsalubrious stretch of Oxford Street.  It was flanked, on the occasion of my visit in August 2003, by an unusual number of shops displaying thigh-high, stilleto-heeled, pointy-toed  boots in lurid shades of PVC on their outside racks, with helpful signs pointing out that they now carry them in men's sizes up to 12EE.  It looked like the kind of discouraging edifice to which Darth Vader might resort for help with his retirement stipend.  Not at all what I was picturing:) 

* or use to mulch their gardens, or line the bottom of their pet containers, or paper the garage walls, or use to note phone numbers, or wrap chewed wads of gum for discard, or...

     If you'd like to write to the webmistress, please direct e-mail to admin at jasonisaacsonline dot com (to reduce spam, this address is not provided as a hotlink; please cut and paste it into your e-mail address line, replacing the words "at" and "dot" with the appropriate symbols).  Diane has kindly offered to respond to general fan questions at diane at portraitplanet dot com.

     Otherwise, check the message board--someone else may have been curious about your very topic!

     Diane's site, http://www.portraitplanet.com/jason.html, features some of her artworks of Jason Isaacs, together with statistical information (she provides the most comprehensive site dealing with the eternal question, "Why does he always die??") and a collection of memorable lines from some of his characters.
Char's site, http://www.jasonisaacsphotoalbumsonline.com/, has a fabulous collection of images from most of his projects and public appearances, plus news about upcoming appearances.

     There's another nice, friendly message board with fans who are delighted to chat about Jason Isaacs (or not!) at the FanZone.

And don't forget to visit here:  http://www.one.org/international/

Updated:  11 August 2008