A quotation is a rough guide to the cost they may be changed until an agreement is made. Can they be altered once it is submitted but before it is accepted by the customer?
Once the quotation is submitted you can not make changes to the prices. Either you can cancel and amend the Quotation or you can create the sales order and change the rates in Sales Order instead.
Thank you @makarand_b I can’t see the amend button you mentioned? I don’t want to chamge the prices but we charge by the hour and the hours may need changing or if that can’t be done a new row added