When a professional services firm contracts to perform a big project, it is common for it to get a request to work at reduced hourly rates. While it may be tempting to discount to lock in the deal, doing so also sets a precedent with the customer and those it talks to, making it more likely that future work will be at the lower rates.
Since a rate, once set, is hard to increase, it is all the more critical to protect it. A good alternative to discounting is to offer a lump sum credit in the contract. Position it as an amount that is earned over the course of the contract so that, the more services provided, the greater the share of the credit is realized by the customer.