The two platforms have been running in parallel since the new Selestia service was launched last year.
Top ups to existing plans will still be possible via the Multifunds platform and a top up tool is being developed to make this easier for advisers during Isa season.
Existing clients on the Multifunds platform will continue to be migrated to SIS where there is demand.
Skandia head of proposition marketing Peter Jordan says: “Following the reduction in costs on SIS financial advisers have been voting with their feet and the Selestia platform is now the clear choice for new business.
“It is therefore the appropriate time to take the next logical step in unifying and refining our platform proposition. For practical reasons advisers will still be able to top up existing investments on the MultiFunds platform and we will continue to work with financial advisers to migrate these policies onto the investment solutions platform over time.”