It depends:
- I always and repeatedly encourage all my clients to keep their own copy of my deliverables. Be that editable files or just straight PDF exports (when editables are not delivered).
- I will never backup files that were circulated and not used. So if a client sends in 500 pictures and we only use 10 in the brochure, i will not save the other 490 pictures when the work is delivered and paid. It is only my actual deliverables that i am backing up. I will also remove all draft PPTs, DOCs, etc we used to complete the job when all the content has been pulled from these.
- For larger clients with ongoing work spread over many years, i actually guarantee 3 to 5 years of backup for everything delivered, included in my fees. This is something we write down in the contract and i will have two identical copies of every job on two separate hdd drives, and in some cases even a third cloud backup.
- For smaller or one-off clients, i will also back up their files indefinitely, but generally tend to clean these up gradually after 3-4-5 years if no other contact has been made for additional work or there is no contract or clause forcing me to keep the files forever.