Understanding of the processes driving the deposition of acidic sulphur, oxidised- and reduced-nitrogen species has improved dramatically over recent years. A simple trajectory model approach is used here to describe the highly coupled behaviour of sulphur dioxide (SO₂), oxides of nitrogen (NO(x)) and ammonia (NH₃). The model is able to reproduce the salient features of the geographical distribution of the main wet-deposited pollutants across the United Kingdom. A feature of the model is the important role played by the oxidation products of sulphur dioxide and nitrogen oxides in determining the distribution of wet-deposited ammonium. Scenarios employing substantial reductions in European sulphur dioxide emissions (based on the 1994 UN-ECE Sulphur Protocol) also produce concomitant reductions in wet-ammonium deposition. This behaviour serves to emphasise the importance of establishing multi-pollutant strategies within the European application of the critical loads approach to nitrogen.