2 years worth of London allowance taxed as a lump sum

I wasn’t given my London allowance for 2 years and then it was all backdated and given to me as a lump sum of £11000. I was taxed about £6000 of it. Seeing as it should’ve been given to me monthly and not put me in a higher earning bracket, if it was paid correctly, will that come back as a tax rebate?

Hi Abigail,
You can expect a reply by 8 June 2024.
Thank you.