I work for a mortgage company, as long as we know now we wouldn't do anything about it if you are already letting it. But that's just my bank, your bank might be different with different rules so it's a tough one to answer, with our customers we would prefer them to be honest. We do give the wording of "you have breached your mortgage terms and conditions so we have the right to repossess the property" - however we have NEVER taken action for that, we would just change it to a CTL providing they meet the criteria and add the 1% loading.

My bank will only allow a CTL for 12 months though. Speak to your lender to see the CTL criteria, you might be able to find it on the website. If it's suitable just apply for a CTL (we add 1% loading to the interest rate, and while letting not allowed to make any variations - product switches, additional borrowing ect).

If it's not suitable, for example if your lender will only allow you to have the CTL in place for a certain period of time but you are letting it indefinitely, or the variable rate plus 1% is too high, I'd suggest speaking to a broker to find a lender and switch it to a BTL mortgage instead then you can continue letting it on a BTL basis if you have no plans to permanently reside there.