Detailed answer — step-by-step actions under Oklahoma law

1) Immediately preserve evidence and protect assets

– Obtain certified copies of the death certificate from the funeral home or the county health department. Banks and card issuers require certified copies.

– Don’t confront anyone in a way that might jeopardize evidence or safety. Instead document suspicious activity: save online account statements, take screenshots of online transactions, keep copies of cards, and write a timeline of who used which account and when.

2) Contact banks and credit card companies

– Notify each financial institution that the account holder has died. Provide a certified death certificate. Ask that the institution place a hold or freeze on transactions pending probate or further instructions. Most banks will not release funds to anyone without court authorization.

– For credit cards, ask the issuer to freeze new charges and to flag the account for fraud review. Ask for a written confirmation of any freeze or action they take.

3) Report suspected unauthorized use or theft

– If someone is using the accounts without authority, report the conduct to local law enforcement and request a report number. Unlawful use of a deceased person’s financial accounts can be criminal (theft, fraud, or exploitation). See Oklahoma criminal statutes for theft and related offenses (Title 21) for general reference: 21 O.S. (Crimes).

4) Start the probate process to obtain legal authority

– To regain legal control of bank and credit card accounts, a court must normally appoint a personal representative (executor or administrator). That person will receive Letters Testamentary (if there is a will) or Letters of Administration (if there is no will). Banks usually accept those court-issued letters as authority to access or manage accounts.

– File a petition for probate in the appropriate Oklahoma probate court. The Oklahoma Probate Code is in Title 58 of the Oklahoma Statutes; consult that Title for procedures and deadlines: 58 O.S. (Probate).

5) Use small-estate procedures if available

– Oklahoma law provides simplified procedures for some smaller estates that can let heirs collect certain assets without full probate. Check the probate code and speak with a probate attorney to see if you qualify. Relevant rules are in Title 58: 58 O.S..

6) What banks and card issuers will typically require

• Certified death certificate(s).
• Official court-issued Letters Testamentary or Letters of Administration (or small-estate affidavit where allowed).
• Valid photo ID for the person seeking access.
• Account numbers or recent statements.

Once the personal representative presents the required paperwork, the bank will typically transfer accounts into the estate or issue checks payable to the estate or its representative so debts can be paid and remaining funds distributed to beneficiaries.

7) Handling unauthorized charges and identity issues

– Dispute unauthorized credit card charges with the issuer in writing and include a copy of the death certificate and police report, if available.

– Contact the three major credit bureaus (Equifax, Experian, TransUnion) to place a deceased person’s file on a fraud alert or note that the person is deceased. This helps prevent new accounts from being opened in the decedent’s name.

8) Civil remedies if someone refuses to stop

– If a third party refuses to return funds or continues to use accounts, the estate (through its personal representative) can sue for conversion, breach of fiduciary duty, or unjust enrichment. The personal representative can also ask the probate court for orders to recover estate property and to hold the wrongdoer accountable.

9) When to get legal help

– If someone is actively spending, moving, or hiding assets, or if there is conflict among heirs, consult a probate attorney promptly. An attorney can file emergency motions with the probate court to freeze assets and stop transfers.

What to bring to the bank or court — a quick checklist

• Certified copy of the death certificate (several copies).
• The decedent’s account numbers and recent bank/credit card statements.
• If available: the original will and contact information for named executor and beneficiaries.
• Your government-issued photo ID.
• Police report number or contact information if you reported illegal activity.
• Contact information for an Oklahoma probate attorney if you have one.

Helpful Hints

• Act fast. Banks and card issuers may remove access quickly; prompt notification increases the chance of preserving estate assets.
• Keep careful records. Save all communications (emails, letters), and keep copies of statements and receipts.
• Ask for written confirmations from banks and card companies whenever they take action.
• Do not sign away rights without understanding the consequences. If someone offers to “help” by moving money, get legal advice first.
• If the estate seems complex or if someone is taking funds, hire an Oklahoma probate attorney — a court appointment may be required to restore control.
• Use certified mail or emailed confirmations to create a paper trail when dealing with institutions.