what forms of depreciation can use the half year convention 
the half year convention can be used with any depreciation methods the internal revenue service irs modified accelerated cost recovery system macrs consists of two depreciation systems the general depreciation system gds and the alternative depreciation system ads which typically has to be elected by the taxpayer unless required by the irs macrs allows for three depreciation methods under gds and one under ads the 200 declining balance 150 declining balance and straight line methods can be used under gds but only the straight line method can be used under ads 3the bottom linethe half year convention for depreciation holds that assets purchased during the year will be treated as if they were purchased in the middle of the year for the purposes of depreciation sometimes the mid quarter convention will have to be used instead these conventions allow a company to better match revenues and expenses in the year in which they are incurred 