Your Nest ID is the unique reference number that starts with "MEM". Keep it somewhere safe, as you will need it whenever you contact Nest or sign in to your account.
You will find it in the welcome pack Nest posted to you when your employer first enrolled you. Nest may also have sent it by email, so it is worth searching for "Nest" in both your inbox and your junk folder. If you have already set up your online account, sign in and go to My account.
I don't have my Nest ID but I want to transfer
You can still go ahead. When you are consolidating your Nest pension into Jarvis, enter your National Insurance number in place of the Nest ID.
I still can't find my Nest ID
Call Nest on 0300 020 0090. They will verify your personal details before giving you the number.
Related: Find and consolidate old pensions