I'm changing from 100 amp to 200amp breaker box. Is just a meter change all that is needed outside. I have the new service wire run. Does the Electric Co. charge for changing the meter?

The meter does not have to be changed, however, the meter base does need to be changed and that may require a new meter.

You need to have this conversation with you local power company.

Depending on the age of your existing service, quite a bit of utility work may need to be done.

Also, did you get a permit for the panel replacement? If you did not, the power company may tell you to pound sand.

Properly sized 200 Amp Service Feeders should be 2/0 copper or 4/0 Aluminimum. Did you use the correct size feeders from the meter to the panelboard?

You may want to get some bids on the work from licensed electricians before you have either the power company or an inspector pull your home off the power grid.

EVERYTHING need to be replaced from the connections at the top of the house, down to the meter enclosure, down to the panel, and all grounding and bonding. ALL this equipment is sized according to the service size.

The power company is responsible for their meter (the glass meter itself) and normally the drop from the street. Both of which they replace at their own discretion.
Underground services are usually different.