Private transfers can affect the spending response to stimulus payments, as those receiving income windfalls may transfer resources to other households in greater financial need. We report a survey experiment where individuals were asked how they would respond to a £500 payment, with a randomly selected subset of individuals explicitly told that all households would receive the same payments (a ‘public windfall’ scenario). This additional information increased MPCs by 11%. Reported transfer intentions in response to windfalls suggest that public payments crowd out private transfers, partly accounting for the higher MPCs in the public windfall case.