Right now, changing the customer (account) on an existing service call isn’t supported. The only editable piece related to that is the contact using “Change contact,” but that doesn’t switch the account itself.
If a call is created under the wrong customer or details need to be changed for the billing entity, the current workaround is only to create a new service call with the correct account.
If this is after the job has been completed then all the linked timesheets & notes etc have to be changed and recreated too.
It would definitely save time in real workflows if we can change the customer account for the service call, ideally to be able to be change customer account up until invoicing is processed and then it can be locked as per the current work flow.