It depends entirely on which Internet Fax service you are using, you did not specify. That being said, most Internet Fax services average between 50-300 faxes per month depending on the monthly plan you choose. The best thing for you to do would be to contact your provider and ask them how many faxes you can send and receive on your plan. If you think it will exceed that amount then you may need to get a higher tier plan or switch providers.
