How can I unlock an iPad that belonged to my late father.

Without knowledge of the passcode, access to any existing data won’t be possible. The best that you can hope for is to be able to eventually reuse the iPad. The key is to recover access to the AppleID account of your late Father.

Quite often, close family members have sufficient knowledge - and access to likely recovery paths - that access to the AppleID account of the deceased family member can be recovered. Having done so, it is then possible to release the Activation Lock that prevents reuse of an iPad/iPhone.

The following guidance is written from the perspective of the owner - but you’ll get the idea as you run through the process.

If your device is Activation Locked, this help page will provide most of the information that you’ll need:

Activation Lock for iPhone, iPad, and iPod touch - Apple Support

If you have forgotten your AppleID or associated password, these can be recovered here:

https://iforgot.apple.com

To recover your credentials, you’ll need access to any one of the following:

• Your primary email address mailbox that corresponds with your AppleID
• Any of the secondary/recovery email addresses that should be configured for your AppleID account
• Any of the trusted telephone numbers (fixed line or Cellular/Mobile) that are associated with your AppleID

Unless you AppleID account has not been fully/correctly configured, or has been seriously neglected, recovery of the AppleID and password should not be difficult.

More information about recovery of your AppleID:

If you forgot your Apple ID - Apple Support

More information about recovery of your AppleID password:

If you forgot your Apple ID password - Apple Support

When you recover access to your credentials, you would be well advised to log-in to your AppleID account from a web browser - and verify/update any email addresses and trusted telephone numbers:

https://appleid.apple.com

Having recovered access to the AppleID account (and therefore the AppleID username and associated Password), Activation Locks can be removed. There are several routes to this, but for brevity, I’ll refer you to this support page:

Turn off Activation Lock – Apple Support

If the passcodes of any devices are unknown, the data stored on the device itself is now gone - but from your question I surmise that data recovery is not you immediate aim. That said, if the device(s) have an associated iCloud backup, you can restore the backup data to the device. To do so, you would need to follow this procedure:

If you’ve forgotten the passcode on your iPad, or your iPad is disabled – Apple Support

You’ll need access to either a PC (with iTunes installed) or a Mac (with iTunes or Finder - as appropriate for the installed version of MacOS). At the end of the process, you’ll have the option to restore data from the backup.

If your intent is to wipe/reset the device(s) for reuse by a new user, you would be best advised to prepare them properly:

What to do before you sell, give away or trade in your iPhone, iPad or iPod touch – Apple Support

I hope to have covered all the likely scenarios - and similarly hope that this guidance is helpful in fully resolving your current difficulties.

How to request access to a deceased family member's Apple accounts - Apple Support may also be appropriate.

Hi. Arthur.

It may be impossible to unlock your Dad's iPad without knowing the password. You have about 10-15 tries, (after waiting the iPad disabled screen timers) after that, you would have to Restore it by taking it to recover mode. Summary: You would have to restore your Dad's iPad if you want to use it, unless you guess the password.

Hopefully this article helps: If you forgot the passcode on your iPad, or your iPad is disabled - Apple Support

I'm pretty sure Activation Lock wasn't existent at iOS 9? Correct me if I'm wrong.

Activation lock was introduced in iOS 7.

https://en.wikipedia.org/wiki/ICloud