Losing credit on electricity meter on registering a new key fob

Hi there

I’m on a prepayment meter for my electricity and gas and have just switched to Bulb.

When my new electric key and gas card arrived, I had letters for each with instructions on topping up and registering the key/card.

With the gas, it says when you register the card with the meter you don’t lose any existing credit on the meter.

However, with the electricity it says when you register the key with the meter all credit on the meter gets wiped.

Can I check that this is correct? If I register my new key will I lose what’s left on the meter?

Thank you