Different UCI number. HELP

It wont affect your application. Is your ULN different or just your UCI?
ULNs should be the same - if they're not then you should ask your college to update your Personal Learning Record to merge the two ULNs.

The ULN is the same thankfully. My university has asked for evidence of results so should I send them my current exam certificate with the changed UCI number, or should I ask my college to send me new certificates for an old UCI number? Also, I'm looking to resit levels so which UCI number should I use?

UCIs can be different
If your ULN is the same and the certificates are in the right name then it's fine you don't need to worry or do anything. Just send scans of the certificates to the university asking for them

Please don't give me false hope. This sort of situation happens 1/1000000 (probably higher), so I presume I'm in a really bad situation. I read that the UCI number is a way of getting all qualifications of a person in 1 place, and if I have 2 UCI numbers, they will think I'm 2 different people, and maybe cheated my way through education. If this is found at a later date I'm afraid very bad things will happen. I'm sorry if this sounds harsh but I'm really worried.

You're confusing the ULN (which is the same throughout education) with the UCI.
The UCI is only used by exam boards not by universities or the DfE Personal Learning Record.
Ask your college to get the 2 UCIs merged if you want but it's completely irrelevant to your university application or the validity of your certificates.

I've read on a few forums by @Compost that UCI numbers should NEVER change. I'm really confused.

it shouldn't change but it's so common for it to end up changed that the exam boards have spreadsheets for centres to merge large numbers of duplicates at once.

https://support.pearson.com/uk/s/article/UCI-Numbers

From a university perspective - we will never look at a UCI number. It's completely irrelevant to us. We *might* use your ULN number to look up your PLR to verify your qualifications.

I've read on a few forums by @Compost that UCI numbers should NEVER change. I'm really confused.

UCIs can be different
If your ULN is the same and the certificates are in the right name then it's fine you don't need to worry or do anything. Just send scans of the certificates to the university asking for them

Hey, just 1 more question. When applying to resit which of the UCI numbers do I choose? Should I choose the most recent one with which I did my A levels with? They don't tell me to include my ULN number so I presume they will get my ULN if I give them either of the 2 UCI numbers (?)

Once again, thanks a lot for the help. I was really stressed but now you've given me reassurance.

Hey, just 1 more question. When applying to resit which of the UCI numbers do I choose? Should I choose the most recent one with which I did my A levels with? They don't tell me to include my ULN number so I presume they will get my ULN if I give them either of the 2 UCI numbers (?)

Once again, thanks a lot for the help. I was really stressed but now you've given me reassurance.

As I said, tell them all 3, but put your A level UCI as the 'main' one, i.e. the one you put in a specific box.

(Yes, if they enter you with a UCI but not a ULN then they will get an error message from most exam boards or for AQA they hear nothing but won't be able to download your results because the ULNs don't match but they give you the info then to be able to fix it and then download again,). Honestly , it's all perfectly fixable but would be so much easier if people followed the rules form the start.

The centre I go to has said that they only use UCI numbers and don't use ULN numbers so I will just put the main UCI number and hope it works out.

Private schools don't use ULNs so this might be why. As I said, it's nothing unusual and it will get sorted in the normal admin - they can just enter the ULN when the exam board makes them do so.,