Sinn Féin has said there are concerns that the planned postal code system could be "another Irish Water".

Sinn Féin’s transport spokesman Michael Colreavy told the joint Oireachtas Transport and Communications Committee that he saw no evidence of an independent trial of the postcode structure for such a fundamental piece of infrastructure.

He said he was concerned about the cost and over-reliance on consultants and "quite frankly" he was worried that it might be another Irish Water.

Niall McDonnell from the Freight Transport Association said Eircode was of no use to people who deliver parcels or pallets and it was only a solution for letterboxes.

Tom Carr from Pallet Express said he was among 100 hauliers around the country and he did not think any were approached about the technical or day-to-day working basis of the scheme.

He told the committee they simply would not use the system if it was imposed on them and he understood the system ticked boxes for other industries around the country but not for transport.

Mr Carr said because there was no sequencing "you couldn’t load various delivery trucks in accordance with it".

Mr McDonnell told the committee that Ireland needs a postcode but not any code.

He said while Eircode is an excellent address database for direct mail, utilities and revenue, it was a bad postcode because it would assign two adjacent properties different randomly assigned codes.

He told the committee that the Eircode system departs substantially from the requirements set out in the last Dáil and the system would put significant costs on small businesses for no tangible benefit.

Mr McDonnell asked the committee to use its influence with Minister for Communications Alex White to forestall the introduction of the Eircode system before it was too late.

Eircode is due to begin in spring 2015. Each code will comprise seven characters unique to each mailing address.