Would renting my flat require a buy-to-let mortgage?

Q My fixed-rate mortgage ends soon, and I am planning to let my property for six-12 months while I take a career break. I understand that if I were in the middle of my deal I would need to seek "permission to let". But since my deal is almost over and I want to re-fix, should I seek a residential or buy-to-let mortgage? My current provider said that after I am granted permission to let I would simply re-fix on another residential mortgage. However, I have seen better rates with other providers, so if I apply for a new mortgage with someone else would it then have to be buy-to-let, or can I apply for a residential mortgage and seek permission to let at a later date? For ease, lets assume my property is already rented by the time I want to remortgage. AW A If we are assuming the property has already been let by the time you want to remortgage, a buy-to-let mortgage will be your only option if you want to change from your current provider. You are also likely to find that any buy-to-let mortgage will be less competitively priced than an equivalent residential mortgage. Another thing to take into account is the fact that with most buy-to-let mortgages the most you can borrow is 70%-75% of the value of your property. This could be a problem if you are borrowing more than that on your current mortgage.