Switching residential to buy-to-let in order to buy new residential

widders

Hi My husband and I have a one bed flat in London currently let out with consent to lease while we have been working abroad. We are looking to move back in a year and know that we don't want to move back into that flat since we need more space/will be trying to start a family. We don't want to lose the flat as it is generating reliable income and is in an area that stands to gain value if we can keep hold of it. We have paid enough off the mortgage to be able to release equity enough for us to get a 2nd residential mortgage (looking at 150K price range) near our families in Birmingham. I understand all of this process, however the buy to let deal which has been recommended to us as the best option is making me a little nervous. We need 75% LTV and we are currently living in China which I understand limits our options. The best offer the adviser I spoke to found is:

5 year fixed
4.49%
Interest Only
Monthly cost - £563
Application fee - £999 (includes all legal costs and valuation)


Does this sound steep even for buy to let? Our other option is to wait until we come home to remortgage but at that point we
a) won't have a house to move back into without kicking out good tennnants
b) will no longer have proof of income and employment since this will be a transitory phase for us of course...

Huge thanks for any advice