The use of insoluble anodes has become critical to the viability of horizontal electroplating equipment. Despite this there have been few reported studies on the impact of using such anodes on the electrochemistry of acid copper plating solutions. A literature search therefore reviewed the different types of insoluble anode that had been previously utilized in sulphuric acid-based electrolytes and from this a number of criteria were established that might be applied when selecting an insoluble anode for horizontal acid copper electroplating. A 'life study' was then carried out to compare two electroplating baths, one operating with standard copper anodes, and the other insoluble anodes.