What to do when an ID number in a contract doesn't match the client's document

When an ID number in a deed or contract doesn't match the number on the client's identity document, the instrument contains an error that must be resolved before anyone signs.

This discrepancy is more common than it might appear, and it's one of the most clear-cut to deal with. Unlike a name, where a variation might reflect a legal change or an abbreviated form, an ID number has no room for interpretation — it either matches or it doesn't.

Why it happens

A transcription error in the draft. The most common source. When copying an ID number from a client's document into the draft, a digit gets transposed, dropped, or pulled from an older version of the same client's file.

The client has a new document. The client renewed their passport or driving licence and the number changed, but the draft was prepared from an earlier power of attorney or a previous transaction file. The new number never made it into the engrossment.

A carry-over from a precedent. In deeds drafted by adapting an earlier instrument, the ID number from the original transaction can survive several review rounds before anyone notices.

What to do before signing

First, establish which number is correct. The correct number is always the one on the identity document the client presents at the point of signing. The deed records what a person typed; the identity document records what the issuing authority certified.

Second, do not proceed until the draft is corrected. Once the error is identified, the draft needs to be corrected and re-circulated before execution. Signing a deed with an incorrect ID number and correcting it by deed of rectification afterwards is a more expensive and time-consuming process than correcting the draft now.

Third, note the discovery in the file. Even if the error is corrected before signing, a brief file note — what the incorrect number was, what the correct one is, and when the draft was updated — protects the firm if the review process is ever questioned.

What not to do

Do not reconstruct a partial number. If the draft is missing digits and the client's document has more, the temptation is to fill in the gap by inference. That is not correction — it is modification of a figure that has not been verified. Only correct what can be directly compared.

Do not assume the most recent document is always the reference. In some identification systems, the number stays the same across renewals. In others it changes. The only way to confirm which number applies to this transaction is the document the client produces at the time of signing.

Do not leave the correction for the day of execution. "We'll sort it out when they come in" introduces a risk that the correction doesn't happen in time, execution is delayed, and the client's day has been wasted. Correcting the engrossment before that meeting avoids all of it.

When the difference is not an error

Some mismatches have a documented explanation — a client whose number was updated following an administrative process with the issuing authority, who can produce the relevant correspondence or notification. In that case, the right approach is to attach that documentation to the file and note the circumstances in the deed.

The distinction between an error and a documented discrepancy is that the second comes with supporting evidence that can be checked. Without that evidence, the position is straightforward: if the numbers don't match, the draft needs to be corrected before signing.

The check that prevents this

Most of these errors are caught — and avoided — by verifying the ID number in the draft against the client's document before the engrossment goes out for approval. Not after the final draft, but before it. The earlier the discrepancy is caught, the fewer people have seen an incorrect version and the less effort the correction takes.