The buyer records output VAT on the purchase and, if the purchase is for taxable business use, recovers the same amount as input VAT in the same return. The net effect is usually zero, but both sides must be reported.
For contractors, the usual cases are services bought from foreign suppliers (software, design or consultancy) and imported equipment and materials.
How Civova handles it
Civova records reverse-charge purchases with both the output and the input VAT, and puts each in its box of the VAT return figures.