Are you a prepaid or postpaid customer?

If you don't turn on roaming, you can't receive sms. wifi is only for apps like whatsapp, viber, Facebook, etc. Texting (SMS) requires a cellular connection

This link might also help https://www.koodomobile.com/en/help/article-categories/travel-0

To answer your question about my status , I pay on a monthly basis and have 4 months left of tab payments. Ddoes this make me a prepaid or postpaid customer or neither??

I’m really confused about messaging abroad. I’m pretty sure that when I’m at home in Canada I can message without using data or cell service since my cell service in my house is very weak or non-existent and yet I can message fine when on wifi. So, I’m wondering why I would need cell/data to send and receive messages when travelling in the UK if I had a wifi connection in a hotel. I really don’t want to pay the large daily add on fee just to message while I’m away for 3 weeks. I don’t need to phone.  Perhaps I should just stick with email? 

It depends on what you’re using.

While in your texting app you have the ability to send iMessages on iPhone and RCS on Android phones. If you have one of these enabled, then yes, it would only use wifi.

The issue becomes is if for whatever reason wifi isn’t working, then the phone will default to SMS so while it’s possible and may be fine, it also is a little risky as well.

If you have a tab to pay every month, then you have a postpaid account.

You can send/ receive message/text/sms without data on, but you need mobile network.

If you just want to use apps and email on Wifi, then you can remove your SIM card or “Airplane mode “ on “wifi” on all the time. 

I think I almost understand what to do now - thanks everyone.  I have an iPhone. I think if I follow the directions below from the Koodo website and toggle Send as SMS off, then I should be able to send iMessages free when travelling in the UK provided I have data roaming off. Is there anything else I need to do before I go?  There was something in the add-ons about adding voice something or other if you wanted to send texts but maybe that was just over a cellular network?  Actually I don’t really understand the difference between I-messaging and texting; I use the words interchangeably which may be one of my problems. 

iMessage for iPhones will attempt to send messages to other iPhone users using a data connection. However, if the data connection for your device or the recipient is too weak to send/receive the message over data, then the message will be sent as a normal text message by default. If this happens you will be subject to the applicable roaming charges for sending an outgoing text, depending if you have Easy Roam or are using pay-per-use rates.

To avoid accidentally sending text messages to other iPhone users when using iMessage, follow these steps:

1. Select Settings

2. Scroll down and select Messages

3. Toggle Send as SMS OFF

If your intentions were to use iMessage only, you don't have to do much, just simple turn on airplane mode all the time while you are in UK.

If you would like to receive the "normal" incoming SMS, you will have to enable roaming. At minimum, you need the international voice roaming add-on in your account. You might already had it as many customers added it when they activated with Koodo. You can sign into self-serve and check the add-on of your plan to see if it was there or not.And Yes, you need to disable "send as sms" in message. Also disable roaming data and cellular if you want to roam without any extra charges.

This article might also help https://community.koodomobile.com/plans-services-232910/easy-roam-understanding-how-you-will-be-charged-while-traveling-7811296 

This is very helpful, thank you. One last question. what do you mean by “normal” incoming SMS. Is this something that there is a charge for. I presume so since you said that I would need to enable roaming. If the airline sent me a text, is that an example of a “normal” text? Thanks. 

Yes, standard communication sent to a cellphone number is SMS (normal text). 

Incoming SMS is free, however your phone must be connected to a cellphone network to receive it. When you connect, a smartphone would try to do other things. Hence we had all type of advice to control those.

SMS is text messages and is done via your cellular connection. Koodo, and basically all carriers, charge for roaming when you’re connected to another network out of country. It doesn’t get sent by wifi, unless you have voice over wifi enabled. And Koodo set it such that you still get charged for roaming even if you’re connected on voice over wifi out of country. I’m guessing most carriers have done it like that as well. Something like imessage can send and receive messages and such using a data connection, if you set it to only do it like that. It kind of works both via data and via SMS.