Short answer. You file the claim in the estate proceeding itself: deliver it, with the supporting vouchers, to the clerk of the court settling the estate, and serve a copy on the executor or administrator. A supporting affidavit must state the amount justly due, that no uncredited payments exist, and that there are no offsets.
What the law says
A claim may be filed by delivering the same with the necessary vouchers to the clerk of court and by serving a copy thereof on the executor or administrator.
Rule 86, Section 9 — How to file a claim. Contents thereof; Notice to executor or administrator. Read the full provision →
What the law says
it must be supported by affidavit stating the amount justly due, that no payments have been made thereon which are not credited, and that there are no offsets to the same, to the knowledge of the affiant
Rule 86, Section 9 — How to file a claim. Contents thereof; Notice to executor or administrator. Read the full provision →
File in the estate case, not a fresh lawsuit
A money claim against someone who has died is not pursued by suing the heirs one by one. It is presented in the special proceeding where the deceased debtor's estate is being settled. Rule 86, Section 9 says a claim may be filed by delivering the same with the necessary vouchers to the clerk of court and by serving a copy thereof on the executor or administrator. Once filed, the claim is attached to the record of the case in which the letters testamentary or of administration were issued, so every debt of the estate sits before the same court that controls its assets.
The affidavit that must support the claim
A claim that is already due must be backed by a sworn statement: it must be supported by affidavit stating the amount justly due, that no payments have been made thereon which are not credited, and that there are no offsets to the same, to the knowledge of the affiant. If the debt is not yet due, or is merely contingent, it is still filed now, supported by an affidavit stating the particulars. And if someone other than the claimant swears the affidavit — an officer of a creditor company, for instance — the affidavit must explain why the claimant is not making it personally.
Claims founded on a written instrument
If your claim rests on a bond, bill, promissory note or similar instrument, you do not surrender the original when filing: a copy, with all indorsements, is attached to the claim. The executor or administrator may demand, or the court may order, that the original be exhibited. If the original has been lost or destroyed, your claim must instead carry an affidavit containing a copy or a particular description of the instrument and stating how it was lost or destroyed. Keep the original safe until the proceeding ends — you may be required to produce it.
What to do now
First find out whether a settlement proceeding has actually been opened for the debtor's estate, and in which court, because the claim is filed in that case. Then assemble the vouchers — the contract or note, receipts, a statement of account showing payments already credited — and prepare the affidavit. Do not wait for the debt to mature: the court fixes a limited period for creditors to come in, and claims presented too late risk being barred. Filing promptly, with a served copy on the executor or administrator, is what preserves your right to be paid from the estate.