Couple of options include Everest (cat# EB11292) or R&D Systems (cat# MAB6595). However, they are only tested for WB (in the event you need validation for other applications).  Also, they are specific for human. Found these using the GenLogica search tool.

http://everestbiotech.com/product/goat-anti-tert-aa597-611-antibody/

https://www.rndsystems.com/products/human-tert-antibody-641101_mab6595

http://genlogica.com/

Though we are not able to recommend a particular Ab, we can give you many sources for anti-TERT as a starting point. Just search here http://www.linscottsdirectory.com/browse/antibodies

for TERT, and follow the "More Info" links to the suppliers' data pages. You can filter for applications and reactivity against human or mouse.

Hope this helps.

this one works awesome in my cells. Good luck!

http://www.rockland-inc.com/Product.aspx?id=34777