Porrima

Mr Porrima was a customer of the Bank of Karabraxos. He once met the Twelfth Doctor, who took a sample of his DNA by shaking his hand so that Saibra could replicate his biology and infiltrate the bank along with the Doctor, Clara Oswald, and Psi. Using Porrima's identity, the Doctor hid a dimensional shift bomb for later retrieval. After his memories were restored by the Teller, the Doctor remembered looking up Porrima along with Saibra and Psi and getting his DNA for the heist. (TV: Time Heist)

Behind the scenes
Mr Porrima's name was not given on-screen, only in the credits.