Hi all, I have worked for a high street bank for 12 years now and was a mortgage adviser for a few of those. Nearly every lender does this for you as long as you are not in any arrears and have not used any payment holidays before. They are really good but be careful.
When you don't make a payment, the interest is added on to the debt and then you end up paying interest on it - just like kafs78 says. It means your debt increases throughout the payment holiday term.
Also, make sure that the bank will not let this affect your credit rating - I can't remember the exact details about this!
However, as long as you make an agreement with them (and do it well in advance of when you need it as I think they need at least one whole months notice before the first payment holiday), then it can be saviour for those of us with poor maternity pay.
Good luck to you all,