An invoice appeal is a law firm’s challenge to a reduction your reviewers made on its bill, and a vendor appeals SLA is the agreed window and set of rules for raising and resolving that challenge. Ten business days is a common choice for the window. It gives the firm time to gather evidence and keeps your approvals moving. Most eBilling platforms let reviewers adjust lines and show the reason to the firm, but the appeal window itself is a policy your department designs, writes into its billing guidelines, and configures where the platform supports it.
What is a vendor appeals SLA?
A vendor appeals SLA is a written commitment that sets how long a firm has to challenge an adjustment, what it must send, who reviews it, and what happens if nobody responds. Without one, appeals arrive by email weeks later, and reviewers reopen decisions they considered closed.
- Window. The number of business days the firm has to respond, counted from a defined start event. Firms expect quick answers now that billing data from about 400 law firms shows average payment times fell from 62 to 50 days in 2025.
- Reviewer. The named person or team who decides each appeal, so the firm always knows who owns the answer.
- Outcomes. What a response can achieve: the adjustment stands, is partly reversed, or is fully restored.
The SLA sits inside the wider legal invoice dispute workflow of adjustments, rejections, and resolution, and it belongs in your outside counsel billing guidelines, which become configured rules in eBilling. A rule firms never agreed to is hard to enforce.
Why does a 10-business-day appeal window work?
A 10-business-day appeal window works because it is long enough for a billing partner to check time entries and short enough to close the matter inside one monthly billing cycle. Five days is often too tight when the responsible partner is in trial. Thirty days lets disputes pile into the next month’s invoices.
On the firm side, two weeks covers pulling time records, asking the timekeeper, and attaching an engagement letter or approval email. On the department side, appeals resolved within the month keep your accruals and matter budgets close to final numbers.
Some departments use five days for small adjustments under a set amount, for example $1,000, and keep 10 days for larger ones. Start with one window, then split it only if the data shows a need.
When should the appeals clock start and stop?
The appeals clock should start when the firm can actually see the adjustment and its reason, and stop when the firm submits a complete response or the window expires. Starting it when a reviewer saves the change is a common mistake.
- Start event. In Counsel Exchange, Onit’s outside counsel portal, a reviewer can send an adjusted invoice back to the firm, which sees each adjustment and its reason and can accept it or appeal with a justification or supporting documents. Tie the clock to that notification.
- Stop event. The clock stops when the firm submits a complete appeal through the agreed channel, or when the last business day of the window ends.
- Calendar rules. Define business days, which holidays count, the time zone, and the daily cutoff. A firm in London and a reviewer in Chicago need the same answer to “is day 10 over?”
Allow one extension of five business days on request, granted by a named reviewer, and record it on the case.
Which invoice adjustments should be eligible for appeal?
Invoice adjustments eligible for appeal are the judgment calls a firm could reasonably contest, such as reduced hours, disallowed expenses, and staffing objections. Mechanical adjustments that apply an agreed term, such as a rate above the approved card, usually need no appeal route.
- Eligible. Block billing reductions, excess hours, expense disallowances, and task-code disputes, where the firm may hold facts your reviewer lacked.
- Ineligible. Rate-card enforcement and agreed caps, where the term was negotiated in advance. A rate challenge belongs in the rate request process.
- Resubmission cases. In Onit, only invoices submitted in US dollars can be adjusted, manually or through automated rules, so a foreign-currency bill that needs a change is rejected and resubmitted. Those cases follow the linked resubmission path used on both invoice channels, and the appeals window does not apply.
What should a law firm include in an invoice appeal?
A law firm should include the affected line, the outcome it wants, a short explanation, and supporting evidence in its appeal. Reviewers can resolve a complete appeal in one pass, so set the requirements out at the start.
- Line and outcome. The invoice line being contested, and whether the firm seeks full or partial restoration of the amount.
- Explanation. Two or three sentences on why the reduction is wrong, written by someone who knows the matter.
- Evidence. Time detail, an approval email for the expense, or the engagement term that permits the charge.
Return appeals that arrive without evidence, with a note on what is missing. The clock keeps running, which encourages complete responses the first time. Cover these requirements in law firm onboarding so firms know the rules before the first dispute.
What happens when the 10-day appeal window expires?
When the 10-day appeal window expires with no response, the adjustment should stand and the invoice should proceed to its final decision, as long as your policy says so in writing. Leaving expiry undefined leaves cases open with no owner.
Acceptance on expiry is the simplest rule, and the one most firms accept when it is in the guidelines. Escalation on expiry suits large or sensitive adjustments, where a named attorney reviews the case before the invoice moves on.
Limit the cycle as well. One appeal and one reviewer response is enough for most departments. A second disagreement goes to a named escalation owner, usually the relationship attorney, within five business days.
How should payment be handled during an invoice appeal?
Payment during an invoice appeal should follow a stated rule: either the undisputed amount is paid on schedule, or the whole invoice waits for the decision. Paying the undisputed amount keeps disputes small and suits firms with good billing hygiene. Holding the whole invoice gives firms a reason to respond quickly and suits repeat offenders.
Remember that an adjustment in Onit does not change the invoice status by itself; the reviewer still approves or rejects. Map that step against your hold rule, and check how open cases affect your eBilling accrual configuration for unbilled and pending spend.
How do you configure and test an appeals SLA in eBilling?
An appeals SLA in eBilling is configured by mapping each policy rule to a platform feature and testing every rule in UAT before go-live. Onit documents the adjustment, comment, appeal, and resubmission features. A dedicated appeals timer, automatic expiry, or automatic routing depends on your specific configuration, so treat those as items to confirm.
- Map the rules. For each rule (start event, window, expiry, hold, escalation), record whether the platform enforces it, a workflow configures it, or a reviewer tracks it by hand.
- Name manual owners. Any rule the platform cannot enforce needs a named reviewer and a weekly check of open cases against the window.
- Test the edges. Run cases for day 9, day 10 at the cutoff, day 11, a holiday in the window, an extension, and a non-USD invoice.
Build these cases into sandbox to production deployment testing, and keep the evidence. A rule that works on a weekday can fail on a bank holiday.
What should legal ops measure on vendor appeals?
Legal ops should measure appeal rate, reversal rate, resolution time, and expired cases, broken down by firm and adjustment reason. These numbers show whether your reductions are fair and whether the window is the right length.
- Reversal rate. The share of appealed adjustments partly or fully restored. Above roughly one in four, review the rule or the reviewer behind them.
- Resolution time. Median and slowest days from firm response to final decision. Aim for a decision within five business days of a complete response.
- Expired cases. The share of adjustments where the window lapsed with no response. A high figure can mean firms are not seeing the reason at all.
Share these figures with firms in quarterly reviews.
Conclusion
An invoice appeal process works when the rules are written down before the first disagreement: a 10-business-day window, a clock that starts when the firm can see the reason, a clear list of what can be appealed, and a defined outcome at expiry. Decide how payment behaves while a case is open, limit appeals to one round before escalation, and confirm in testing which parts your platform enforces and which your reviewers track. Then measure reversals and resolution time, so the policy stays fair to firms and firm on your budget.
How Basla can help
Basla provides delivery teams for enterprise legal management and eBilling software implementation, covering legal technology consulting, business analysis, billing guideline and appeals policy design, invoice validation and adjustment configuration, vendor onboarding, testing, documentation, and post-go-live support. Basla teams have delivered matter management and eBilling across 10+ global jurisdictions.
Basla business analysts map each appeals rule to what your platform can enforce, and QA teams test the window, expiry, and currency cases in UAT before firms start submitting.
Frequently asked questions
What is an invoice appeal in legal eBilling?
An invoice appeal in legal eBilling is a law firm’s challenge to an adjustment a reviewer made on its invoice, such as reduced hours or a disallowed expense. A vendor appeals SLA sets how long the firm has to raise it and how it is resolved.
How long should a law firm have to appeal an invoice adjustment?
A law firm should usually have 10 business days to appeal an invoice adjustment, counted from when it can see the adjustment and its reason. That window fits within one monthly billing cycle.
What happens if a firm does not respond within the appeal window?
If a firm does not respond within the appeal window, the adjustment normally stands and the invoice proceeds to a final decision. The outcome should be written into your billing guidelines so it applies consistently.
Can every invoice adjustment be appealed?
Not every invoice adjustment needs an appeal route. Judgment calls such as hours and expense reductions are usually eligible, while rate-card enforcement and agreed caps are usually excluded because they apply terms the firm already accepted.
Should the invoice be paid while an appeal is open?
Whether the invoice is paid during an appeal depends on your stated rule. Many departments pay the undisputed amount on schedule and hold only the disputed lines, and some hold the whole invoice until the decision.
Does Onit include a built-in vendor appeals timer?
Onit documents invoice adjustments, vendor-visible reasons and comments, firm appeals on adjusted invoices in Counsel Exchange, and linked resubmission of rejected invoices. An appeals timer, automatic expiry, or automatic routing depends on your configuration, so confirm it during implementation testing.
*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.*