Spousal lifetime access trusts can help ultrawealthy couples reduce estate taxes, but advisors must be careful when both spouses establish them. The transfer uses part of the donor spouse's lifetime gift and estate tax exemption, and the beneficiary spouse can receive distributions according to the trust's terms. The key is to make sure the two SLATs are economically different, said Martin Shenkman, partner at the estate planning boutique law firm Shenkman Tietz. READ MORE: The estate planning 'haircut' advisors should know aboutWhy clients might use SLATsWhen structured properly, SLATs can offer clients some estate planning advantages. Beyond basic estate planning benefits of SLATs, they may also be used in tax basis planning.