The same data shows that around a quarter of those who reregistered had not started to practice.
The NMC says it will write to all those affected by the closing of the register.
Andrea Sutcliffe, NMC Chief Executive and Registrar, said: “We remain incredibly proud of the nurses and midwives who joined the Covid-19 temporary register.
“The height of the pandemic was a frightening time for us all, but thousands of professionals stepped forward to help support essential health and care services.
“They have made a vital difference to people’s lives and we’re immensely grateful for their contribution, particularly in the Covid-19 vaccination programme.
Ms Sutcliffe continued, “Professionals will not be able to practise with temporary registration after the end of March 2024.
“We’ll be writing to everyone on the temporary register shortly to advise them of next steps. We’ll also use the next six months to support those who wish to continue practising to transition to our permanent register.”