Once tenders are in we are not permitted to enter into further negotiations with the firm selected, and until the agreement is in place we must continue to communicate formally with the supplier. We may however work with them to clarify or refine the final content of their offer. If there are a number of communications with minor changes, one clear way of concluding matters is for Procurement to obtain a final confirmation of the requirement from the client department, then request a Full and Final Offer from the supplier containing all of the minor revisions to the specification.
In parallel with this Procurement will be negotiating the contract terms and conditions that will apply to the deal with the supplier. As a general rule we should never accept a supplier's terms as the basis for agreement, and it is normal for them to receive a draft contract along with the Invitation to Tender documents.