The present study builds upon existing research, introducing a novel research question and innovative statistical predictions. It constitutes the first comprehensive time-series analysis of tax incentives for charitable giving among donors in Switzerland and is among the few globally to project charitable deductions. Utilizing unique panel data covering the entire Geneva taxpayers’ population from 2001 to 2011, we forecast future scenarios of donors and charitable deductions. This period also coincided with a legal reform that increased ceilings for charitable deductions. Various time-series forecasting models were applied, and the model with the lowest score (indicating superior performance: best model) was chosen to project future predictions. The best model predicts a total donation amount in the range of 79 to 114 million for the years 2012–2022. These projections provide insights into the scale of deductions, aiding in decisions related to tax incentives for charitable giving. Moreover, they shed light on the key factors influencing these predictions, enabling more informed decisions on the ceiling of tax incentives for charitable contributions.