144 free visa to shanghai

Yes, your itinerary:

Hong Kong - Shanghai - Macau

Is definitely eligible for 144 hours visa free transit in wider Shanghai area.

All you have to have in mind is that your both flights should not have any additional landing with the mainland China with the exception of that one in the Shanghai wider area.

Okay thank you,
Yes I will only be flying direct to Shanghai spending 3/4 days there and flying direct back to Macau.
So this is correct, and there is no issue with me holding a UK passport and also a HKID.

Also, it is correct that I apply for this free visa when I land in Shanghai airport?

It is your passport important and not HKID in this particular case. So, when you land in Shanghai, you will approach 144 hours visa free transit counter where you will present your flight ticket for Macau and also your accommodation booking confirmation if asked for this detail. After that, you will be granted a temporary entry permit and you will be free to leave the airport and to stay, explore and to travel within the entire area comprising Shanghai and also Zhejiang and Jiangsu provinces as you wish.

Perfect! Thank you for your help.
One last question, I am staying with a friend who lives in Shanghai. Do I have to approve a hotel booking or my friends address etc?
Or is it best booking a hotel instead.

Thank you

You can stay with your friend, this is perfectly fine, but you will have to supply the immigration authorities with the identity of your friend, address and the phone number. Also, after you are allowed to exit, you will have to register yourself at PSB (Public Service Bureau) within 24 hours, in reality a police where your friend can assist you. In my opinion, you should definitely stay at your friend... Why would you spend on a hotel when you can stay comfortable at your friend!? Also, this is perfectly legal.

Okay.
What is the documents I need to prove of my friend! His Personal ID Or Chinese Visa ID. And a written document of his address and phone number!

All you need is to arrive at PSB (Public Security Bureau) together and he should bring his personal ID. Also, he can bring his passport with a relevant visa as well, although a personal ID alone should be perfectly fine. You should bring your passport and just bring your flight tickets, just for a case. This will be perfectly enough.

Okay, thank you for your help. Iv seen on some sights about your return flight to your third country you have to have a seat allocated already. But is this true, as I can’t book a seat on my return flight as it’s not an option.

No, this is an outdated information because the Chinese authorities are well aware that something like this is impossible in many cases. You can just forget about this detail and proceed with your travel plans :)

Perfect!
Do I have to provide anything when I land in my Third Destination? As my 3rd destination is Macau but I will be leaving Macau for Hong Kong via the bus when I’m back. Just wondering as Iv came from Shanghai to Macau?

All you need is just your passport. Nothing else. Also, after you land in Macau, you are free to return to Hong Kong by bus or in any way as you wish.