SIM only, can old number be transfer on a certain day?

[MJ602]

I have just ordered a SIM only and have provided a PAC code, just wonder if the number can be transferred on a set date? As my old number is still with the old provider these few days.

thanks

[bristolian]

A mobile number is ported the following working day after you submit your PAC.

If you do this as part of a new order, the PAC is usually treated as submitted the same day that you activate the new SIM on what will be a temporary number. If that is a weekend, then Monday.