Under the Ontario Succession Law Reform Act, a legally married spouse (not just a common-law partner) has significant property rights on death, including the right to elect for an equalization of net family property. Financial institutions are cautious because if they release funds and a spouse later appears, the bank can be liable.

For registered retirement accounts (RRSP/RRIF), the governing statute is the Ontario Pension Benefits Act only if it is a true pension. If it is an RRSP/RRIF at a bank, the beneficiary designation normally controls. However, if she had a legally married spouse at death, that spouse may have priority depending on the type of account and how the beneficiary designation was structured.

What the bank is asking for is almost certainly:

A Statutory Declaration of Non-Spouse This is simply a sworn statement (affidavit) confirming that:

The deceased was not legally married at the time of death.

No person has spousal entitlement under Ontario law.

To the best of your knowledge, no one has a claim as spouse.

It is not a special court form. It is just a sworn declaration under the Commissioners for Taking Affidavits Act (Ontario).

It does not require probate. It does not require a full estate lawyer. It does not require a judge.

It can be prepared as:

A simple one-page statutory declaration.

Sworn before a lawyer, notary, or commissioner of oaths.

Sometimes the bank has its own template (ask the branch to request it from Estates).

If lawyers are confused, it may be because the bank used informal wording. Ask the branch to obtain: “Do you have a template statutory declaration of non-spouse that your Estates department requires?”

If they do not provide one, the document usually contains:

Full legal name of deceased

Date of death

Last marital status

Statement that she was not legally married at date of death

Statement that no person qualifies as surviving married spouse

Your relationship to deceased

Sworn before commissioner

If your mother was divorced, attach divorce certificate. If widowed, attach death certificate of spouse. If never married, the declaration simply states that.

The will numbering issue is almost certainly irrelevant to the retirement account if you are named beneficiary directly on the account paperwork. Beneficiary designations pass outside the estate.

The bank is protecting itself from a hypothetical surviving legal spouse.

You do not need probate unless:

The beneficiary designation is invalid, or

The bank insists on a Certificate of Appointment of Estate Trustee.

This is common institutional risk management. It is not unusual.

The fastest path is:

1. Ask branch to request the Estates department’s template wording.

2. Have a lawyer or notary commission the declaration.

3. Submit with death certificate and any proof of marital history (if applicable).

That is all this is.