No limitations apart from Local CLI or invalid CLIs as explained in In-Country, Local, or No-CLI Calls Rejected.
Other Features or Restrictions
When placing calls to any recipient using Vonage Voice products, you will need to ensure the destination phone number is formatted correctly.
You must not add a 1 to the number after the country code, for example, 5218180264283, and the number should be dialed at 10 digits only, for example, 528180264283.
For more information, see the Voice Numbers Features Overview.