My experience is that over the last 5 years corporate rates with hotel and car-hire chains have become meaningless. The hotel chains themselves largely accept this.

The large chains have several corporate rates (or bands) dependent upon your business. So your company may have a negotiated rate, which in effect is a 'Band C' rate.

Thousands of other companies will have negotiated rates which are also 'Band C', so when you call reservations and quote your 'company code', their system just translates that into a 'Band C' rate.

Because everyone and there mother now belongs to some group or other which gets a corporate/group/discounted rates, the hotels will normally offer these irrespective of your right to them. You will also find that the corporate rates are VERY often not as competitive as other quoted discount rates!

The exception to this is rates negotiated with INDIVIDUAL hotels which are often very competitive.

In a nut-shell, if you call reservations and they don't quote you a rate as good as a corporate rate - hang up!

If you want to test this, look at a corporate rate on www.hilton.com, compare this to your company rate (if you have one) and compare that to the best available rate.

Airlines are slightly different, discount fares are usually subject to achieveing revenue targets. Therefore tickets are usually charges gross and at a later date a bulk rebate is made to the travel agent.
Nick