Following on from some completed freelance work, I have received a request for ongoing support to help in house resources build upon the work already provided.
The company is approximately 1 hour round trip away, and I expect this support work to be relatively brief (at most 1-2 hours), which puts me in a difficult position as far as charging is concerned.
My rate is quite high, but the cost of travelling would probably eat 10-25% of the final invoice, which is not a small amount. I would like to cover this with a call out fee (which on my first thought would essentially be equivalent to 1 hour at usual rate + a little extra for fuel, to covers both my time and my costs) but I am unsure if this would be unexpected or non-standard.
Is it unusual for software freelancers to charge a call out fee for a small piece of work like this? If it is appropriate, does a call out charge based on my rate for time + other expenses seem reasonable?