Old number change how lonh

If you mean porting your number from another network to Smarty :

1, Text PAC to 65075 from your current SIM 

2, Your PAC code will arrive by text within 60 seconds

3, Activate a Smarty SIM card, and then within your Smarty account dashboard, give Smarty the PAC code from your old network.

4, Your number will be transferred  to Smarty within two working days, possibly just one working day (NB - Numbers do not port / transfer between networks on weekends, only Monday to Friday)