I need to know if it is possible to program a Toshiba DK16 and a DK40I phone system with a 10 button toshiba phone. I do not have a 20 button phone available. I need to remove the PIC code for long distance.

If you're using program 54 in LCR then you won't need a 20-button phone.

If what you are trying to program doesn't use buttons 11-20 then yes, you can use a 10 button phone.

For as little as a 2020SD costs, why don't you just buy one to program?