Does international phone numbers work without the + in the beginning?

I'm trying to buy a ticket online but I'm buying them from a foreign country. To confirm my identity when I'm going, they asked for my phone number. The website doesn't allow + in the beginning and here's my question: Will my phone number work without the + in the beginning with just the country/area code? If not, what can be a replacement of the + in the beginning? Thanks!
Asked Mar 19, 2017

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