An invoice submission deadline for a closed matter is the last date a law firm can bill against that matter, and the trailing invoice window is the period between closure and that date. Set well, the window gives firms time to send final invoices for work already done and then shuts the matter to new charges. Set loosely, closed matters keep collecting invoices for months, accruals never settle, and final spend figures keep moving after everyone has stopped watching.
What is a trailing invoice window?
A trailing invoice window is the period after a matter closes during which outside counsel can still submit invoices against it. It exists because legal work and legal billing run on different clocks: a firm finishing work on the 28th may not issue the invoice until its next monthly billing run, two to six weeks later.
Three dates define the window:
- Closed On date. The date the matter is marked closed in your ELM platform. Work after this date should be rare and explained.
- Run-off period. The number of calendar days firms are given to bill after closure, such as 30, 60, or 90.
- Cutoff date. The last date an invoice is accepted. In Onit Unity this is the matter’s Invoices Accepted Prior To date, and once that date passes, vendors cannot bill against the matter.
Treat the window as the financial close of the matter.
How does an ELM platform enforce an invoice submission deadline?
An ELM platform enforces an invoice submission deadline by storing a cutoff date on each matter and refusing new vendor invoices once that date has passed. In Onit Unity, closing a matter fills in the Invoices Accepted Prior To date from the system-level run-off period, counted in calendar days.
For example, a matter closed on October 1 with a 30-day run-off gets a cutoff of October 31. Firms assigned to the matter can bill until then, and the platform stops accepting their invoices afterward. A run-off of zero ends the window at closure.
Two details matter in configuration. The run-off is counted in calendar days, so weekends and public holidays fall inside the window. The run-off is also set at system level, and in SimpleLegal the system-level run-off defaults to 0 calendar days, so every matter starts from the same rule, and any matter needing a different date has it changed individually. That consistency is useful, and it makes the governance of individual changes important. The closure step itself is one of the matter closure controls that decide what locks and what keeps running.
How long should a trailing invoice window be?
A trailing invoice window should be long enough for firms to issue a final invoice on their normal billing cycle and short enough that accruals and budgets close within one quarter. For most departments that means 30 to 90 calendar days, with 60 a common middle ground. Nothing in the platform requires 60 days; the length is a policy choice you configure.
- Firm billing cycles. Firms that bill monthly in arrears need at least 30 to 45 days after the last day of work. Firms billing quarterly need longer, or a request to send a final invoice early.
- Your guideline terms. If your outside counsel guidelines already require invoices within, say, 60 days of the work, a matching window avoids two deadlines firms have to track.
- Finance close. A window that ends before quarter-end close lets the final number land in the right period.
- Matter type. Litigation with trailing expert or court-reporter costs often needs longer than a closed transactional matter.
Align the window with the deadlines in your outside counsel billing guidelines.
What happens to accruals during the run-off period?
Accruals continue during the run-off period, because the matter can still receive invoices. In Unity, vendors on a closed matter keep receiving accrual notifications until the Invoices Accepted Prior To date, which acts as the cutoff for both accruals and invoices.
This surprises firms more often than legal teams. A firm receiving an accrual request on a matter its own lawyers consider finished will either submit a zero, ignore it, or ask why. Tell firms at closure that accrual requests run until the cutoff, and ask for a final estimate of any unbilled time in the first request. Finance needs those numbers quickly, since a 2025 survey of 100 finance professionals found half of finance teams take six or more business days to close the month. A firm that reports zero unbilled time on day five has effectively closed its side of the matter 25 days early, and you can treat any later invoice from it as an exception worth a question. Those requests follow your eBilling accrual configuration, so agree the closed-matter behavior with finance when you set it up.
When should a matter use a zero-day window?
A matter should use a zero-day window when billing after closure would be unexpected or inappropriate. A zero-calendar-day run-off stops post-closure accrual requests and removes the vendor’s ability to submit invoices once the matter closes.
- Fixed-fee matters. Where the fee was paid in full on completion, any later invoice is a billing error.
- Matters closed in error or duplicates. Closing a duplicate matter should stop all billing against it immediately.
- Matters already reconciled. When final invoices are approved and the firm has confirmed nothing is outstanding, there is no reason to keep the window open.
Because the run-off value is system-level, a department with a 60-day default handles these cases by setting the individual matter’s cutoff date to the closure date.
Who should be allowed to extend an invoice cutoff date?
Only a small group of authorized users should be able to extend an invoice cutoff date, and every extension should carry a reason. A cutoff later than the Closed On date can come from the run-off rule or from a manual change by a user with the right permissions, so the invoice audit trail has to show which.
- Named approvers. Limit cutoff changes to eBilling administrators plus the matter’s responsible attorney or a legal operations lead, typically two to four people.
- A required reason. Common legitimate reasons include a trailing expert invoice, a disputed invoice being resubmitted, or a firm’s billing system outage.
- A bounded extension. Extend by a fixed period, such as 14 or 30 days, and avoid open-ended dates far in the future.
Report extensions monthly by matter and firm. A firm needing an extension on one matter in twenty is normal, and a firm needing one on every matter has a billing process problem.
How should firms be told about the final invoice deadline?
Firms should be told about the final invoice deadline at the moment the matter closes, with the exact cutoff date and what happens after it. An automatic platform notification helps, and a short direct email from the matter owner makes it stick.
- The date itself. State the calendar date, such as October 31, and skip phrases like “within 30 days.”
- What to send. Ask for all remaining fees and expenses, including disbursements still to be billed by third parties.
- Confirmation of nothing outstanding. Ask the firm to confirm in writing when nothing further will be billed.
Build the closure notice into your standard firm communications.
How should late and resubmitted invoices be handled?
Late and resubmitted invoices should be handled differently, because one is a missed deadline and the other is a correction. Most eBilling platforms record a rejected invoice and its resubmission as two separate submissions, so your reporting needs to tell them apart.
- Late invoices. An invoice arriving after the cutoff is refused by the platform. Decide in your guidelines whether the firm loses the fees or can request a one-time extension with a reason.
- Resubmissions. A corrected invoice for one rejected before the cutoff should be judged against the original submission date. Allow a short correction period, such as 10 to 15 days, through a controlled extension.
- Disputes in progress. Keep the cutoff open, or extend it, while an appeal on an earlier invoice is unresolved.
How do you test and measure trailing invoice window rules?
You test trailing invoice window rules by closing test matters under each configuration and confirming the cutoff date, accrual behavior, and invoice acceptance on both sides of the date. Run at least five cases before go-live: a standard run-off, a zero-day matter, a manual extension, an invoice on the cutoff date itself, and an invoice the day after.
After launch, track the median days from closure to final invoice, the number of invoices refused after cutoff, extensions by firm, and the share of closed matters with confirmed final spend within 90 days.
Conclusion
An invoice submission deadline for closed matters turns matter closure into a financial close as well. Choose a run-off length that matches firm billing cycles and your finance calendar, use zero-day cutoffs where billing should stop at once, control who can extend a cutoff and why, and tell firms the exact date when a matter closes. With those rules configured and tested, closed matters reach a final spend figure on schedule, and late surprises become rare exceptions with an audit trail.
How Basla can help
Basla provides delivery teams for enterprise legal management and eBilling software implementation, covering legal technology consulting, business analysis, matter closure and invoice run-off configuration, accrual setup, billing guideline alignment, testing, documentation, and post-go-live support. Basla analysts turn your closure policy into configured cutoff rules, and the QA team tests every closure scenario before firms rely on it.
Basla teams have delivered matter management and eBilling programs across more than 10 global jurisdictions, and the delivery bench stays on through hypercare while the first closed matters work through their run-off periods.
Frequently asked questions
What is an invoice submission deadline for a closed matter?
An invoice submission deadline for a closed matter is the last date a law firm can bill against it. In Onit Unity this is the matter’s Invoices Accepted Prior To date, and vendors cannot bill once it has passed.
What is an invoice run-off period?
An invoice run-off period is the number of calendar days firms can keep billing after a matter closes. When it is greater than zero, closing the matter sets the cutoff date automatically.
Is a 60-day trailing invoice window standard?
A 60-day window is common, though the length is a configurable policy choice. Most departments choose between 30 and 90 calendar days based on firm billing cycles and their finance close.
Do accrual requests continue after a matter closes?
Accrual requests continue after closure until the invoice cutoff date in the matter record. Setting the run-off period to zero stops them at closure.
Can an invoice cutoff date be extended?
An invoice cutoff date can be changed manually by a user with the right permissions. Each extension should record the approver, the reason, the new date, and when the change was made.
Are resubmitted invoices counted separately?
A rejected invoice and its resubmission usually appear as two separate submissions in eBilling reporting. Judge deadline compliance against the original submission date.
*This article is provided for general information only and does not constitute legal advice. Basla Solutions provides legal technology implementation and support services and does not practice law.*