There is no such thing as a 'coat of arms for a surname'. Many people of the same surname will often be entitled to completely different coats of arms, and many people with that surname will be entitled to no coat of arms. Coats of arms belong to individuals. For any person to have a right to a coat of arms they must either have had it granted to them or be descended in the legitimate male line from a person to whom arms were granted or confirmed in the past.

It is a popular misconception that the term 'crest' describes a whole coat of arms. It does not. A crest is a specific part of a full achievement of arms: the three-dimensional object placed on top of the helm. The helm and crest are not always shown in depictions of coats of arms. It is not possible for somebody to have a crest without having a coat of arms.

There has recently been a spate of shops, organizations and websites selling heraldic plaques and other items purporting to represent coats of arms associated with a specific surname. Their sources are unofficial, unreliable and outdated printed works of reference, which are far from comprehensive and contain numerous errors and omissions.

The College of Arms is the official registry of armorial bearings and pedigrees for the United Kingdom (excluding Scotland) and the Commonwealth.

The Court of the Lord Lyon is the official registry of armorial bearings and pedigrees for Scotland. Information leaflets from the Lord Lyon's office may be found on the Electric Scotland website.

Useful information on Scottish heraldry is also provided on the website of the Heraldry Society of Scotland.

In addition, the Cambridge University Heraldic and Genealogical Society provides a useful directory of heraldry sites.