How Long After a Neck Lift Will I Be at Risk of a Blood Clot?

First - if a neck lift is done under local with IV Sedation - the risks should be extremely low.  You should be up and around the next day and early ambulation is the key.  If you can avoid General Anesthesia - you reduce most of the risk of DVT.

Dear patient from GA
I reviewed other physician’s answers. Their answer is regarding Deep Vein Thrombosis (DVT) which is very unlikely after neck lift surgery, if you’re ambulating. Many of my patients ask this question as well. I believe your question is what are the chances of bleeding and clot formation after neck lift surgery. The first post operative week is crucial to have enough rest and stay away from heavy lifting, bending, and exercise. I hope this is was helpful.
 

The risk for a blood clot after a neck lift is typically low and is more related to associated factors such as prior history, birth control pills, obesity, age, etc.  

I assume you mean a deep vein thrombosis which is very rare to occur. Some have even occurred several weeks after surgery.  Early ambulation and preop dvt prevention techniques help  minimize the risks.