I received a text this morning from AppleUK saying "your apple id has been locked for security reasons. Unlock your Apple id at" then a second text which was a link to an apple site. tje link in the text said bit.do. Is this a scam pleaee ?

It is indeed a scam. If your Apple ID was locked, you will get an email from Apple, not a text. Report the phishing text here.

To report spam or other suspicious messages that you receive through iMessage, please send them to imessage.spam@apple.com.

Identify and report phishing emails and other suspicious messages - Apple Support

It's a scam. Apple will not send you a notification that your Apple ID is locked.

Regardless, if you feel that your Apple ID has been compromised, I suggest that you take a look at the following link:

If you think your Apple ID has been compromised - Apple Support

Balloonmoon wrote:

Unfortunately I didn't ignore it. I'd just updated 2 nights previous to 10.3 and I thought it was relates to that. I put in my username and password. Soon after (about 2 minutes)I did it I realised it could be a scam so I changed my password and logged out. Do I need to do anything else do you think?

Just be sure you signed in to the real Apple website to change your password. If you want to take extra precaution, call your credit card company and ask them to replace it (the credit card you use at Apple online store).

It's a scam! Ignore it!!

That address (bit.do) is often used to hide the real scammer's website address.