A well has an outer housing with a vertical main bore and a wing bore. The well is completed by: running an upper completion into the well; locating a tubing hanger in the main bore of the outer housing for fluid communication with the wing bore, the tubing hanger including a services line connected to downhole equipment; connecting a further services line to the services line of the tubing hanger, after the tubing hanger has obtained said operational position; and installing a cap on an end of the main bore. The connected services lines are arranged to communicate a service between the tubing hanger and an exterior of the capped well through either or both of: the end of the main bore; and the cap. Related apparatus, a cap, and a tubing hanger are also described.