We're an electrical contractor company with the same issue. Sales and installation is done at different project locations often for the same customer.

We resorted to using 1 of the 3 available custom fields on forms as 'Job Location'. The good is, unlike 'ship to', the field can be used in reports to, for instance, see all the work done at specific locations. The bad is it's limited to like 25 characters so we've resorted to street address only and truncated when too long. Manually entering it can lead to typos which requires even more time to manually track down and fix. And you still end up needing 'ship to' for proper sales tax anyway.

We're now attempting to use quickbooks built in 'location' field which has to be enabled in the settings. The good is there is no character limit, locations get saved in a drop down menu for future reuse, and they can be used in reports. The bad is, there's no way to include the location field on customer forms so we're still forced to use 'Job Location' custom field as detailed above, and it can't be used for sales tax so we're still forced to use 'ship to'.

It's lame. How are service companies and contractors handling this?