Mortgage costs rise as banks confirm higher rates

why are they being increased?

Many homeowners could face higher monthly payments after some of the UK’s biggest lenders confirmed mortgage rate increases.
https://www.bbc.co.uk/articles/c72pnzq483vo

Given the prevalence of 2 and 5-year fixed rate deals in the UK mortgage market, quoted mortgage rates rising slightly isn't really the cause of higher mortgage costs for households per se. It's a small part of the picture.
Even if mortgage rates had been falling for the last couple of months, households coming off their existing mortgage deal would still face a massive uplift in mortgage costs regardless of any of the recent month to month changes in quoted mortgage rates.

so what is the reason why the economy is causing higher interest rates?

In short: to sustainably quell the currently elevated and quite persistent rate of inflation.
UK mortgage rates largely reflect the swap rate for it's respective maturity, as well as a margin for the mortgage provider. Swap rates reflect market expectations of the future direction of the interest rate set by the Bank of England. The BoE sets the rate of interest at a level it believes will return inflation to its 2% target in the medium term (roughly two years). As a result, interest rates/swap rates/mortgage rates currently reflect the BoE's view on the level of inflation persistence there is - primarily through the lens of services inflation and private sector regular pay growth - i.e. how long it will take for inflation to sustainably return to target.

I thought that inflation is going down albeit slowly?

I thought that inflation is going down albeit slowly?

Yes, and this is why the Bank of England is starting to consider cutting interest rates. The first cut is likely to take place in the June-September period.

What will inflation be in 18 months time?

good.

you tell me.