Backdating consent forms
In theory, this would appear on the face of it to be a reasonable request, as it is just a private arrangement between two parties. This is a fraud on the tax authorities, a criminal offence and is likely to get the lawyer who prepared the document disciplined by his regulator and possibly also charged as a co-conspirator. The event did not happen during the time period required for the benefit so an attempt is being made to pretend that it did.
Two parties in a business contract who explicitly agree in writing that an effective date for the contract can be made at a date prior to the current one. The position is then clear to all who subsequently look at the document. However, he only realizes this in January and so wishes to backdate the document to December. He also has no way of knowing whether the backdating will be scrutinized by a regulatory authority or even a Court. Backdating, in this case, may be useful as the parties, who have already begun acting on the agreement, finish the final details of the written contract.
For example, if a seller had sold his house in December then the seller could have taken advantage of certain tax benefits. These are questions he will probably be asked by the judge or regulator if things go wrong and to which he will need convincing answers.
This is not an agreement that could have been made orally. There are some ways in which the lawyer can give himself some protection in agreeing to such a request but they are not foolproof. The argument is obviously not valid if the transaction is one which is required by law to be in writing such as a transfer of land. If allowed, up to six-month backdating would apply as long as the buyer pays for that time period. Similarly, a person who wants to buy health insurance and make it effective beginning at a date prior to the current date.