GP leaders said only a handful of practices would hit the target and raised concerns about how responses were being collated.
Practices have reported that PCT data underestimate true response rates.
Under the choice and booking directed enhanced service (DES), GP practices ask patients they refer to hospital to complete surveys to say whether they were offered a choice of four hospitals.
Survey responses will generate payments worth around £6,000 per average practice if more than 60 per cent of respondents say they were offered choice.
But practices should also receive a payment for carrying out the survey.
This is worth 2.8p per registered patient, but is only paid if more than 1.5 per cent of a practice's total registered population completes the survey.
However, GP leaders say practices are unlikely to have referred 1.5 per cent of their patients in the 11-week period - from 15 January to 30 March - measured by the DES. Even if they did, it would be unlikely that all of these patients would complete the survey.
In addition, GP leaders have pointed out that the mechanism disadvantages practices that are efficient, and so refer less.
GPC negotiator Dr Andrew Dearden said: 'The more you refer, the easier the target is - that's a perverse incentive.'
Hove GP Dr Nigel Higson said Brighton and Hove City PCT had told him that no practice in the area hit the payment threshold.
Dr Higson said his 10,000-patient practice referred around 180 patients in the 11-week period, more than 1.5 per cent.
But despite being 'enthusiastic users of Choose and Book' and asking patients to complete surveys after consultations, the PCT said only 0.77 per cent of the practice population responded.
'We think around 90 per cent of patients we referred completed surveys, which would mean we hit the target. It's not a lot of money; it's the principle,' Dr Higson said.
The GPC says the pay system was publicised in January, but Dr Higson said many GPs were not aware of it and had not kept records to prove response rates.
GPC negotiator Dr Richard Vautrey said fears that the target was unachievable had prompted the GPC to secure a reduction to it during negotiations.
LMCs contacted by GP said they were not aware of any practice that had hit the target. The DoH confirmed that the £1.5 million allocated for surveys had not been claimed by PCTs.Survey pay
- Practices receive 2.8p per registered patient if more than 1.5 per cent of their list completed the survey.
- Only patients who were referred can be asked if they received choice.
- GPs say target is 'unachievable'.