With there being so many types of mortgage, there are a few important questions you should consider asking the mortgage broker / lender (and yourself)...

What happens if I need to move house within the term of the mortgage?
Most mortgages are now portable, so moving house doesn't have to involve agreeing a new deal (this fact is particularly important if you have redemption penalties within the terms and conditions of your mortgage). However if you need additional funding, be careful to choose the right product so that the end dates of your exiting scheme and new scheme are similar, enabling you to move both mortgages if necessary to secure a better rate.

Are there any extended redemption penalties?
What happens at the end of any special deal? While most people accept they will be penalised for moving their mortgage or repaying during the initial period, some lenders continue to charge redemption penalties even after this; hence the word "extended". These penalties are dying out as more lenders enter into the market with more mortgage types and as people and the media have become more aware of them.  However, it is still best to check.

Does the lender charge daily interest?
Daily interest means the amount you owe is recalculated every time you pay money off. This means you pay less interest over the life of the mortgage.  With annual interest you don't get the benefit of 12 months' payments until the end of the year. It can make a huge difference to what you pay. If you had 10 years to go on your £115,000 mortgage, a 5.35% deal charging daily interest would actually be better value than a rate of 5% where interest was calculated annually.

Can I overpay on the mortgage...?
Many mortgages restrict the amount of money you can overpay (each lender varies te amount however generally you would be looking at around a maximum of £500 a month or 10% of the outstanding mortgage per year). You can incur penalties if you go over these limits and so you need to be aware. In some cases, although the extra money you pay is taken off your outstanding debt for the purposes of calculating the interest you owe, the lender might keep these sums in a separate 'pot'. You can draw on this in the future either by taking back a lump sum, or using the surplus to cover your monthly payments.

...or take payment holidays?
Be careful and make sure you read the terms and conditions of the mortgage carefully if you feel you will want to use this feature during the mortgage term. Typically you can arrange to miss one or two payments, and your monthly payments are then recalculated to spread the cost of the payment you missed over the rest of the life of your mortgage. There could also be an extra penalty or administration charge on top.