Yes, you can run the same ad content on different accounts, but it’s not 100% safe depending on the ad platform.
Most ad platforms (Facebook, Google, TikTok) don’t care about identical creatives by themselves — the issue is WHY multiple accounts exist. If the accounts are connected (same IP, same billing info, same device, same business), the platform may flag it as circumventing systems, which is a big violation.
If the accounts are legit and unrelated (e.g., different clients, agencies, or separate businesses), running identical ads won’t cause a problem. Platforms see the same ads from different advertisers all the time.
So the real risk isn’t the ad content — it’s the account setup. If the accounts look like duplicates from the same owner, you could trigger a restriction.