There are no formal requirements for phlebotomy training as there are no governing bodies in the UK.
However, NHS trusts came up with guidelines and framework for competency that we follow in our course.
What you get at the end of the course is a certificate of attendance/completion.
With the certificate of attendance/completion, you will have a better chance of getting a job, bearing in mind that most phlebotomy applicants have no previous experience, and you will be ahead of everyone with your training confirmation.
The certificate is a proof to your dedication, commitment and knowledge. You are ready to start practicing, and once you get competency you can apply to higher and better paid job quicker than other candidates.