Reference checks?

Hello I’m currently undergoing reference checks, and the letting agents had my 3 months bank statements, can someone let me know why they require this ? I’m just a bit worried because if it’s to check that I’ve been paying rent I won’t have any sign of that on my statement as I previously lived with my ex with a shared tenancy but the rent always came out of his bank, I provided my old letting agent to the new letting agents so surely they’d be able to contact them and confirm that I was on the tenancy and all rents were paid ?? Also what can make you fail referencing, I’ve got decent credit score, stable income etc I’m just stressing at this point lol also what is the earliest a reference check can come back ?

hi Abi and welcome! Try not to stress, three months banks statements are to check affordability and to check that youre not living beyond your means or having gambling issues etc. Is there any sign of money being transferred to your ex bf account? Make sure you explain things to them about the rent. Agents have seen every scenario.
The agents will almost certainly check with the previous agent to verify if you have paid rent on time.
You could fail a reference if things you have said dont stack up, also CCJS and none payment of dept, or salary reported is incorrect. They are checking if you are “reliable” thats all. Credit checks usually very quick 2-3 days, getting response from employer and previous agent may take longer as people arnt always that responsive.