I'm currently a pay as you go customer but my new phone is on its way for a monthly tab plan. I'm wondering if I can transfer and keep my number to that phone? I signed up saying I am a new customer and I'm not sure if that effects that.
Signing up for a new account is the good thing to do. Next step is to port over your Koodo prepaid number. It's like porting in from a different carrier. Also, you can go online and apply for postpaid service, you'll need a new sim as the prepaid sims are only good for prepaid. Koodo will run a credit check and send you a new sim card. Just pop the new sim into your phone and off you go.
If you're keeping your number you can set everything up right online. Just keep your prepaid service active so you can port the number over to the new sim. You can still use the same phone too!
Switching in either direction is like moving to a completely different company. The SIMS won't work, you will lose whatever investment you have in minutes, tab, etc. Your self-serve become historical and you have to re-register all over again. So best to do it when you've just about exhausted your account.