A careful reader's guide to what statutory forms and online will services handle well, the five situations where they reliably fail, and the signing rules that void a valid-looking document.
Someone has handed you a printed will, or a login to a will service, and asked whether it is good enough. That is a narrower question than whether do-it-yourself estate planning is a good idea in general, and it has a better answer. A fill-in-the-blank document is a set of decisions poured into a standard container, and the container holds fine for standard decisions. The work is in reading what was actually written, checking it against the family it describes, and knowing which four or five facts turn an adequate form into a document that will fail at exactly the moment nobody can fix it.
What the forms do competently
Statutory forms and the better online services handle outright gifts to living adults without difficulty. Everything to a spouse, and if the spouse has died first, everything split equally among the children, is a structure that has been drafted thousands of times and is hard to get wrong on a form. Naming a guardian for minor children works the same way, because the document is only a recommendation to a judge, and the form's job is to record the parents' preference clearly. Health care directives and HIPAA authorizations are often the strongest part of a packaged plan, since many states publish their own approved form and the service is simply reproducing it.
A durable financial power of attorney sits in the middle. The form is usually fine; the problem is that banks and brokerages apply their own acceptance rules, and a document nobody has shown to the institutions may be refused years later when it is needed. A careful reader takes the signed power of attorney to each bank while the person is still competent and asks whether it will be honored, or whether the institution insists on its own form as well.
The five situations where forms reliably break
Blended families are the first. A form that leaves everything to the current spouse, with the children from a first marriage taking whatever is left afterward, does not actually leave them anything, because the spouse inherits outright and can redirect it entirely. Property in two states is the second, since real estate is governed where it sits, and a second parcel usually means a second probate unless the deed or a trust is restructured. The third is a beneficiary who receives needs-based assistance. The Social Security Administration oversees the income and resource tests that govern Supplemental Security Income, and a plain outright bequest to that person can disqualify them; the fix is a properly drafted special needs trust, which no form provides.
The fourth is a closely held business or a rental portfolio, where the will disposes of an interest that an operating agreement or a buy-sell contract may already have promised elsewhere. The fifth is the heir everyone expects to contest: a disinherited child, an estranged sibling, a caregiver who moved in late. Forms give you no drafting choices that make a challenge harder, and the ordinary protections, contemporaneous capacity evidence, an attorney-supervised signing, sometimes a no-contest clause with a token gift, are procedural rather than textual.
The signing rules that void a valid-looking document
This is where good documents die. Most states require two witnesses who watch the signature and sign in the testator's presence, and many disqualify or penalize a witness who is also a beneficiary, which means the daughter who drove her mother to the kitchen table should not be one of the two. A notary is usually not a substitute for witnesses; the notarized page is a self-proving affidavit that lets the will be admitted without tracking down those witnesses later, which is a convenience, not a substitute for the signing itself. Check the date on every page, the initials where the form asks for them, and whether anything was handwritten after the witnesses left.
Check also that the will is a single complete document with no stapled additions, that the executor named is willing and alive, and that a superseded will has been physically destroyed rather than filed alongside the new one.
What a careful reader does next
Read the form against the family, not against the instructions. Write down every fact the document does not know: the stepchildren, the cabin in another state, the nephew on disability, the LLC, the son who has not spoken to anyone since 2019. If that list is empty, the form is very likely enough. If it has one entry, take that single entry to an attorney and pay for a narrow piece of work rather than a full plan.