I have a lease on a flat in a building where all the flat leaseholders have the same length lease and all own a share of the freehold. Our leases expire in 60 years and we have all decided to extended our lease to 999 years at no cost (because we are paying the notional lease extension premiums back to ourselves). Is SDLT payable?

Note: In a past post to this forum " Lessees' own company is freehold reversioner- effect?" posted February 2008 on a very similar query, Jeffrey Shaw of Nether Edge Law replied: "Lessees who already own freehold and grant themselves new leases simply returns capital to themselves without taxable consequences." which would imply that the answer to my question is "No". Can anyone confirm that this is correct?