What are the procedures for transferring social security from Taizhou to Nantong?

The account has not been transferred. Specifically, you need to provide an ID card account book, but the social security center fills in the application for the transfer and continuation of endowment insurance and medical insurance, and the social security department where your unit is located (Nantong) issues a transfer contact letter. Then, the social security center of the transfer-out place (Taizhou) issues relevant insurance vouchers, and goes through the transfer-in formalities with the social security of the transfer-in place with the insurance vouchers. This set of procedures is very complicated, so it is best to go around by yourself and ask the unit to go to the social security center to ask for relevant forms and fill them out.

Further reading: How to buy insurance, which is good, and teach you how to avoid these "pits" of insurance.