Short answer

Yes — you can and should ask a co-owner to produce mortgage statements, proof of payments, and repair receipts before proceeds are divided. Under Missouri law, a co-owner who pays mortgages, taxes, insurance, or repairs may be entitled to reimbursement or contribution from other co-owners, and a court that orders a partition sale can require an accounting. If a co-owner refuses to produce documentation, you can seek an accounting or raise the issue in a partition action so the court can decide whether reimbursements are owed and how sale proceeds should be distributed. See Missouri partition statutes: RSMo Chapter 525.

How Missouri law treats payments and contributions between co-owners

When two or more people own real property together (as tenants in common or joint tenants), each owns a share of the whole. Missouri’s partition statutes allow a co-owner to ask the court to divide or sell the property if co-ownership breaks down. The court can order a sale and distribute proceeds after satisfying liens and lawful claims. The sale proceeds are not simply split mechanically; the court can require an accounting to determine:

which mortgages, liens, and encumbrances must be paid from proceeds;
whether any co-owner made payments (mortgage, taxes, insurance, necessary repairs) that should be reimbursed or treated as advances; and
how to allocate net proceeds according to ownership shares after allowances for necessary expenses and proven contributions.

Because the court handles these issues in a partition action, you can request documentation and a formal accounting through the court process if informal requests fail. See RSMo Chapter 525 for partition procedures: https://revisor.mo.gov/main/OneChapter.aspx?chapter=525.

What documentation is reasonable to request

Before dividing proceeds, reasonable documents include:

Mortgage statements showing the mortgage balance and any payments made.
Canceled checks, bank statements, or electronic payment confirmations proving mortgage or tax payments.
Invoices, receipts, and paid contractor bills for repairs or improvements.
Proof that repairs were performed (before/after photos, contractor communications).
Insurance payments, tax bills, and receipts for other property-related expenses.

These documents let a court determine whether payments were necessary, whether they preserved the property or benefited all owners, and whether one co-owner is entitled to contribution or an adjustment when proceeds are divided.

What to do if a co-owner refuses to provide records

If a co-owner refuses to cooperate, you have practical and legal options:

Send a written request (keep a copy). Be specific about the documents you want and give a deadline.
Offer mediation or a neutral accounting to narrow disputes and reduce litigation costs.
File a partition action in Missouri circuit court. In that action you can ask the court to sell the property and require an accounting. The court can order discovery and compel production of documents.
If there’s an urgent risk (e.g., co-owner hiding documents or encumbering the property), ask the court for interim relief or to preserve evidence.

How courts typically handle mortgage payments and repairs

General principles courts use:

Liens such as recorded mortgages attach to the property and generally must be paid from sale proceeds in priority order before owners split the remainder.
A co-owner who voluntarily pays a mortgage or makes necessary repairs to prevent loss may be entitled to contribution from the other co-owners for their share of those expenses, provided the payments are proven and reasonable.
Payments that improve value (capital improvements) may be treated differently than necessary repairs; the court can adjust distribution for equitable reasons.
The co-owner seeking reimbursement should present clear, contemporaneous records (statements, receipts, proof of payment). Without documentation, courts are less likely to award reimbursement.

Practical steps to protect your position

Follow these steps to preserve rights and make a stronger claim for reimbursement or contribution:

Demand documentation in writing. Specify mortgage account numbers, date ranges, and types of receipts needed.
Keep your own records: copies of any payments you make, communications, and photos of repairs.
If you pay payments to protect the property, use traceable methods (checks, wire transfers) and get receipts.
Preserve communications (texts, emails) that show agreement or refusal to contribute.
Consider a partition action if informal resolution fails — the court can force discovery and order distribution that accounts for proven advances.

When to get a lawyer

If the amount at stake is significant, a co-owner refuses to cooperate, or the title and lien issues are complex, consult a Missouri real property attorney. An attorney can:

advise whether your payments are likely to be reimbursable;
draft written demands and preserve evidence correctly;
file a partition action or a contribution claim and handle discovery to compel records; and
negotiate an agreed accounting or settlement to avoid protracted litigation.

Helpful hints

Ask for mortgage statements and receipts early — the more time before sale, the easier to resolve disputes.
Get receipts and invoices in the co-owner’s name or showing payment from the co-ownership account when possible.
Make payments through an account traceable to you and keep copies of cleared checks or bank records.
Document why repairs were necessary (safety, preventing further damage) to support reimbursement claims.
If you reach an agreement, put it in writing and record how sale proceeds will be adjusted to reflect reimbursements.
Use the partition process under RSMo Chapter 525 to force accounting and sale if cooperation fails: https://revisor.mo.gov/main/OneChapter.aspx?chapter=525.

Common pitfalls to avoid

Relying on informal promises without written proof.
Failing to preserve payment records or photo evidence of repairs.
Assuming a court will automatically split proceeds evenly without considering liens and proven advances.
Waiting too long to act — delay can make discovery harder and evidence less reliable.