Pre-Paid plans are similar to pay-as-you-go SIM cards. You pay in advance for an amount of minutes and data, and once you’ve ran out, you need to top it up.

Anyone can get this type of plan, even tourists. You will just need to provide a copy of your passport and your tourist Visa.
To get a Prepaid SIM you don’t need to be a UK resident, so short term visitors can also buy one of these.

Post-paid plans refer to a monthly contract attached to a SIM card. You will pay monthly for your mobile services.

UAE Residents will need to present their Emirates ID to get a Post-Paid phone contract. Until you have this, it’s recommended to get a Pre-Paid SIM.
For this, you’ll need Proof of Identity, Proof of UK Address and a UK Bank Account.