About Application for Letters of Testamentary / of Administration / with Will Annexed
To apply for letters testamentary, letters of administration, or letters of administration with will annexed to establish authority to manage a decedent's estate.
When you'd use it: When initiating probate proceedings in Boone County Circuit Court, Probate Division, following a person's death.
Where to get the official form
The official version of Application for Letters of Testamentary / of Administration / with Will Annexed is published as a PDF by the Missouri courts. We checked this link and it resolved to a form on an official court or government website — always download the current version directly from the source rather than a third-party copy:
Download Application for Letters of Testamentary / of Administration / with Will Annexed (PDF) →
Source: courts.mo.gov
Link last checked: May 31, 2026
How to file Application for Letters of Testamentary / of Administration / with Will Annexed in Missouri
- Step 1 — Confirm you have the correct formUse Application for Letters of Testamentary / of Administration / with Will Annexed when when initiating probate proceedings in Boone County Circuit Court, Probate Division, following a person's death. Double-check it's the right form for your situation — Missouri probate forms are revised periodically, so verify the name and number against your court's current form list before you start.
- Step 2 — Complete every required fieldFill out Application for Letters of Testamentary / of Administration / with Will Annexed carefully and review it for errors before filing. Probate cases can already take months — a small mistake on the form can set your timeline back further.
- Step 3 — Get it notarized or witnessed if requiredSome probate forms must be signed in front of a notary or witnesses. Check the instructions on the form itself, and arrange notarization before you file if it's required.
- Step 4 — File it with the correct courtSubmit Application for Letters of Testamentary / of Administration / with Will Annexed to the probate court or county clerk handling the estate — usually in the Missouri county where the deceased lived. Ask the clerk how they prefer to receive filings (in person, by mail, or e-filing).