Proton Drive provides up to 1GB of cloud storage for free across all Proton accounts. The Proton Drive Plus plan extends this storge allocation up to 200GB in total whilst the Proton Unlimited plan extends this event further to 500GB (in addition to providing some other account benefits as well). Other storage options include up to 3TB being available via the Proton Family plan plus business orientated accounts which provide customisable levels of storage for those requiring more via a consultation with the Proton sales team beforehand.