Hi, I've never seen commercial fasteners for pots, but if you can get some flat steel bar, and cut it to fit inside the pot, mark where the drainage hole is and drill a hole in the bar, then drill a hole in whatever it is that the pot is going to stand on, and screw into it, then fill the pot with your compost, Derek.

I think, as Derek says, that the only way of securing it will be to put a fixing in the floor beneath it and fit a short chain or something through the drainage hole into a short bar laid across the base of the pot. There should be room under the pot for any fixing because you can stand the pot on feet (which is good practice anyway). That way the fixing is out of sight, too

Thanks. I've seen a few suggestions for chains around lumps of concrete and just assumed that someone, somewhere would have come up with a fancy fixing.
Off to the drawing board ...

Urbanite why do you feel the need to fix your container to the ground - with the weight of soil/compost in it the container isn't going to move.

Are you worried about theft? I have had pots for over 30 years and have never secured them and have never had any go missing (most are far too heavy) but I suppose it depends on the area you live in? Look around your area if others have nice pots outside then its likely yours will be ok too.
I would be more concerned about new pots being frost proof also I put them on feet so they are less likely to get ants etc.

I'd rather not offer the opportunity to the low-life in this town. I've had pots stolen before (some very nice antique chimney pots a few years ago) and I just don't want to spend money on pots for them to disappear.
No such thing as too heavy - a pot full of soil isn't going to bother anyone who can see an easy couple of quid at a car boot sale.

Never had a problem but we live in a rural community and leave all sorts of things out. Reality is if someone really wants to steal one of your containers they will... think bolt cutters.

Some useful advice from Bob Flowerdew on MoreTh>n website (other garden experts are available!)
http://inside.morethan.com/garden-theft-in-full-bloom/

Several police websites also offer advice but not with any details. Sad fact is that this can happen anywhere and is going on at the moment in Kidderminster to the extent that it is making the newspapers.