Welcome to Vodafone Community
Ensure you have roaming allowed on your account @gbc-gbc
Check your tariff Terms.
Further information in Vodafone and costs/travelling-abroad.
Look in your myvodafone for roaming / abroad.
Customer service on 191 and Live Chat can help you too.
I'd also suggest to check your phone is tri band so it'll work on those networks and also I'd suggest to have it unlocked so you can use a local sim card if you need to.
Current Phone > Samsung Note 20 Ultra 5G - SM9860 Snapdragon.
Samsung One Ui 2.5 / Android 10.
The first thing to ask is if you are pay monthly or PAYG? This thread can then be moved to the correct board where you will receive an good response for your tariff.
To roam in the USA or Canada you will need a quad band phone, if you are using an iphone this should support the frequencies used in the USA and Canada.
If you are on a pay monthly red entertainment plan, you should have Global Roaming Plus added to your account and this will mean you will be able to use your phone without incurring the pay monthly daily roam further charge of £6.00 per day.
There is further information for you here: Vodafone Global Roaming
If you need further help and cannot find the answerd you need from the website, I would suggest using live chat, they will be able to check your account and advise further.
Thank you, I will check up on my account settings wrt roaming. I believe that my iPhone should work in both countries.