First of all, is a Border Terrier a suitable dog for and your family? Do some research into the breed and remember a new puppy will grow into a dog who will hopefully live a long and happy life.
Where to look for a Border Terrier puppy? My first port of call would be to contact the Breed Club secretary in your area, the Breed Club web sites are on the links page, the club secretaries details are shown on the sites. Any problem, drop a note to this web site via the contact page with a rough idea of your location, eg county.
Another place is the Kennel Club, and the “Buying a Dog” tab on the front page of the web site. The next tab is “Find a Puppy” which will take you to reputable breeders with puppies available. Links to the Kennel Club site are on the “Links” page under the Community tab.
Border Terrier Welfare, links on an adjacent page , are always looking for good homes for Borders in their care, it’s a good place to make enquires, but remember to find out as much as possible about the Border Terrier you are re-homing
Another option is to look for a Border Terrier from a reputable breeder who may have a dog that needs a new home. These Borders can be dogs that didn’t make it to the top in the show ring, or maybe just didn’t enjoy showing. To find this type of Border contact the Breed Club secretary in the area where you live or consider visiting shows where Border Terriers are being shown. Ask exhibitors, they may be able help you find a suitable companion.
Try and avoid classified adverts, free papers and dubious web based advertisements.