Short answer

Yes — under South Dakota law you can challenge a sibling’s use of a deceased parent’s bank account before anyone is officially appointed personal representative, but your options depend on how the account is titled, whether there are survivorship or beneficiary designations, and whether the sibling had actual authority. You can contact the bank, seek emergency court orders, and file for appointment of a personal representative to protect estate assets.

Detailed answer — what you need to know under South Dakota law

This section explains the legal framework and practical steps you can take in South Dakota when a sibling is withdrawing money from a deceased parent’s bank account and making mortgage payments before a court has appointed an administrator or executor.

1. Who controls the money right after death?

How the account is titled matters most:

• Account in deceased’s name only: Generally, funds become part of the deceased’s estate and no one has automatic authority to use those funds for personal purposes after death. The funds should be preserved for creditors and beneficiaries until the probate court appoints a personal representative.
• Joint account with right of survivorship: If the account was jointly owned with the sibling and includes a right of survivorship, the surviving joint owner typically inherits the funds automatically and can legally use them. Banks commonly treat joint ownership as survivorship unless the account paperwork says otherwise.
• Payable-on-Death (P.O.D.) or transfer-on-death designations: If the account names a beneficiary, the funds generally pass directly to that beneficiary and avoid probate.
• Revocable or irrevocable trust: If the funds were held in a trust, the trustee’s authority will depend on the trust terms.

2. Potential legal claims if the sibling used estate funds without authority

• Conversion or unjust enrichment — taking or using estate funds for personal benefit may be actionable.
• Action for accounting — beneficiaries can ask the probate court for an accounting of estate assets and transactions.
• Petition to remove or limit a personal representative — if someone is later appointed and has misused funds, the court can remove them or order restitution.

3. Emergency steps you can take immediately

Do these quickly to preserve assets and legal options:

1. Get the death certificate. Banks will require a certified copy to freeze or change access.
2. Contact the bank in writing. Ask what type of account it is (sole, joint, POD, trust) and request a written transaction history for the period after death.
3. Do not confront the sibling in a way that destroys evidence. Communicate in writing and preserve copies of all messages and documents.
4. File a petition with the probate court to open probate and request appointment of a personal representative or emergency (temporary) administrator with limited powers to protect the estate. South Dakota’s probate statutes (Uniform Probate Code provisions) govern appointments and administration — see the South Dakota Codified Laws for probate procedures: https://sdlegislature.gov/Statutes/Codified_Laws
5. If mortgage payments are being made and you fear the funds will be wasted, ask the court for a temporary injunction or emergency relief to freeze disputed account funds pending resolution.

4. Practical considerations about mortgage payments

Mortgage payments from the deceased’s account may be lawful if a surviving joint owner has rights to the account, or if payments preserve real property and reduce loss to the estate. Courts often weigh whether continued payments protect estate assets (e.g., prevent foreclosure) against the risk of unauthorized depletion. The probate court can authorize payment of necessary expenses from estate funds after appointment of a personal representative.

5. How to challenge the sibling’s actions in court

1. Open probate by filing a petition in the county where your parent lived. Ask for appointment as personal representative or for the court to appoint one. The probate process and related procedures are part of South Dakota’s codified laws (see https://sdlegislature.gov/Statutes/Codified_Laws).
2. If immediate preservation is necessary, request temporary administration or an order freezing the account to prevent further withdrawals pending appointment.
3. Ask the court for an accounting for all post-death transactions and for relief to recover improperly used funds (restitution or surcharge against the person who withdrew funds).
4. Provide evidence: bank records, communications, proof of account ownership and beneficiary status, and any documentation of mortgage obligations.

6. Evidence and burden of proof

You will typically need clear documentation to prove (a) the account was solely in the decedent’s name, (b) withdrawals were made after death, and (c) funds were used without authorization for personal benefit. Keep certified copies of the death certificate, bank statements, and any letters or receipts showing payments toward the mortgage.

7. When a bank may freeze or release funds

Banks have different policies. Many will freeze accounts when they receive a death certificate. Others may honor survivorship or POD designations and release funds to joint owners or beneficiaries. If the bank wrongfully releases funds, the estate (through a representative) may have a claim against the bank or the person who received the funds.

Helpful Hints

• Check account paperwork first. Ask the bank whether the account is joint, POD, or in trust.
• Preserve evidence: save emails, texts, bank statements, and certified death certificate copies.
• File probate early if estate assets are at risk. A petition starts the court’s authority and allows the court to issue protective orders.
• Consider temporary emergency relief. Probate courts can grant temporary authority to protect property before full administration.
• Communicate in writing. Written requests and demands create a record for court proceedings.
• Get an attorney for contested matters. A lawyer can draft petitions, request emergency relief, and present accounting and restitution claims in court.
• Keep mortgage and property interests in mind. Preventing foreclosure may justify limited payments, but those must be authorized by the court when possible.
• Act quickly. Delay can make recovery harder and allow funds to disappear or be spent.

How to find the right court resources: Start with the probate clerk in the county where your parent lived. You can also review South Dakota’s codified laws online at https://sdlegislature.gov/Statutes/Codified_Laws for the probate chapters (Uniform Probate Code provisions) that describe appointment of personal representatives, emergency administration, and estate administration procedures.

Disclaimer: I am not a lawyer. This information is educational and does not constitute legal advice. For legal advice tailored to your situation, consult a licensed South Dakota attorney experienced in probate and estate litigation.