A panel change is, by all accounts, a straightforward, and frequent request. With that being said, without visiting your home ahead of the work date, we don’t know where your panel is located, whether it may need to be moved to be electrical-code-compliant, if it is grounded or ungrounded, whether your power supply runs underground or overhead, what amperage you currently have and anticipate you will need in the future, the electrical loads your panel currently supports, and the list goes on. Suddenly, what seems like a simple procedure has become far more complex, and being quoted over the phone leaves you susceptible to being overcharged in the end due to work taking longer than expected, different materials needed, more labour involved, etc. 

While it may seem inconvenient at the time to arrange for a site visit before being quoted, it pays off in dividends because you know that the quote you receive will be reliable and accurate. Any tradesperson who is quoting over the phone is not only jeopardizing their company in the event of a lawsuit being opened for higher final costs, but you are also at risk of being charged more than you had budgeted should the work end up costing more than you were originally quoted.