mysql datatype for telephone number and address

I want to input telephone number in a form, including country code, extension

create table if not exists employee(    `   
      country_code_tel   int(11),
      tel_number         int(10),
      extension          int(10),
      mobile             bigint(20)
);

If tel_number is larger than 15 bit, which datatype can I use, I'd better use Bigint(20)?

create table address(
      address           varchar(255),  
      city              varchar(255),
      country           varchar(255),
      post_code         int(11)
);

For example, if I have a country code for Canada I can use +2 or 002. Which is better for processing?

Thanks for your advice.