Do Wills drafted by Will writers who are not law firms always require witness affidavits for the Grant of Probate application?
TLDR version: No. While there are specific guidelines on when an affidavit of due execution is required, none of them depends on whether the Will was prepared by a law firm or a non-law firm provider.
Sometimes the Court may require additional submissions, such as witness affidavits, during a probate application. Since extra work is involved, this can lead to additional fees at the Grant of Probate stage if such a step becomes necessary.
However, the request for a witness affidavit does not arise simply because the Will was prepared online or because it was not signed off by a lawyer. Likewise, a Will prepared by a lawyer is not automatically exempt from ever requiring a witness affidavit during the probate process.
A good litmus test is to ask the law firm or Will provider whether they can guarantee that their Wills will never require extra affidavits when applying for probate. The honest answer is that no one can provide such a guarantee.
During the probate process, the Court may request further clarification. This can result from issues such as illegible handwriting, corrections in the document, confirmation of execution (i.e. the signing of the Will), or even an error made by the firm when submitting documents. The Court may also require more assurance that the Will was executed properly, for example, that it was not signed under undue influence or fraud.
While there are specific guidelines on when an affidavit of due execution is required, none of them depends on whether the Will was prepared by a law firm or a non-law firm provider.
You can read more about the affidavit requirements in the Family Justice Courts Practice Directions by clicking on the image below:

Unfortunately, when the Court requests a witness affidavit, it does not provide the specific reasoning. You will simply be informed that one is required, without details such as “the Will requires a witness affidavit because it was signed one month before the deceased passed away”. This understandably has led to speculation about the reasons behind the request.
On our side, some Wills drafted through getArrange have been granted probate without any request for witness affidavits, while others have required them. Such requests apply equally to Wills prepared by all providers, including law firms.
In reality, no one can know in advance whether the Court will request extra submissions until the Will is filed. What we can do is follow best practices and include clear signing instructions within the Will to minimise the likelihood of such issues.
If you are concerned about other companies or firms making unfounded claims, you may wish to consider using PKWA Law through the Consult Lawyer function on our platform for your Grant of Probate application.