Mortgage Interest relief capped

Hi I have claimed mortgage interest relief for a property I let. My statement says it has been capped at a figure that relates to my tax liability. I thought it was the amount being claimed that was capped but my statement shows it's the original finance cost that has been capped. To clarify my tax liability is £750 and I'm claiming tax relief for finance costs of £1800, but that has been reduced to £750 and my tax relief is therefore 20% of £750 not 20% of £1800 as I was expecting. Can you explain please?

Hi CazCan62,
The relief is limited to the tax due on any profit that you make.
Please see guidance here:
Tax relief for residential landlords: how it's worked out
Thank you.