House purchase- just about to sign 'contract & transfer' paperwork- can someone with more brain cells than me explain this paragraph to me?

[tiredemma]

it states-

The contract also provides for a penalty interest rate, which is stipulated to be 4% above the base rate of Barclays Bank Plc. This penalty rate will only apply should the contract be breached'

sorry for being thick- I cant ring the solicitors because its saturday- I really want to get this paperwork igned and sent off today. Its taken bloody six months to get this far.

If you don't complete on time then you will be charged interest. The interest rate is 4% above base rate. Standard clause which hopefully won't be needed.

thank you. Ill sign it pronto. (hardly likely to not complete on time- we have been desperate to get to this stage for months)

thanks again (im not thick normally- just exasperated)