Block Billing: How to Detect and Reduce It in an eBilling System

Block billing is the practice of recording several separate tasks in one time entry with a single total, so the client cannot see how long each task took. It is one of the most common reasons a legal invoice gets flagged, and one of the easiest to catch once your eBilling rules are built for it.

What is block billing?

It is a time entry that combines two or more tasks into one narrative and charges one total for all of them. You can see the total hours, but you have no way to judge whether each task took a reasonable amount of time.

Here is an invented example of a lumped entry:

> 03/14 | Senior Associate | 6.2 hours

> Review deposition transcript; draft summary memo; call with client re settlement; revise motion to compel; email opposing counsel.

Five pieces of work share one 6.2-hour figure. The narrative is detailed and the time is opaque, which is exactly the problem.

Why do outside counsel billing guidelines prohibit block billing?

Outside counsel billing guidelines prohibit lumped time because an entry that hides the time spent on each task cannot be reviewed, benchmarked, or challenged.

• Reasonableness. A reviewer can judge 0.5 hours for a client call. Nobody can judge 6.2 hours for five tasks.
• Inflation risk. A California fee arbitration advisory repeats an earlier committee view that lumping tasks may increase billed time by 10 to 30 percent.
• Fee recovery. Where fees are recoverable, courts scrutinize lumped records. In one federal appeals decision, the court cut the requested attorney hours in half, from 820.5 to 410.25, citing records that lumped several tasks together among other gaps.
• Reporting. A lumped line lands under one task code and distorts every spend report built on it.

The clause in your guideline document does little on its own, because billing guidelines change firm behavior once they become configured eBilling rules that run on every invoice.

What does a block-billed time entry look like compared with task-based entries?

A block-billed time entry shows one total for several tasks, while task-based entries split the same work into separate lines, each with its own hours and UTBMS task code. Here is the same 6.2 hours, recorded correctly:

• 1.6 hours, L330 Depositions. Review deposition transcript of plant manager.
• 1.2 hours, L330 Depositions. Draft summary memo of deposition testimony.
• 0.5 hours, L120 Analysis/Strategy. Call with client regarding settlement position.
• 2.6 hours, L250 Other Written Motions and Submissions. Revise motion to compel.
• 0.3 hours, L250 Other Written Motions and Submissions. Email opposing counsel regarding motion to compel.

The total is identical, and the review is completely different. You can now ask why a revision took 2.6 hours, compare the deposition summary with other firms, and see that the client call was reasonable. Splitting costs the timekeeper about a minute a day and saves the reviewer far more on every invoice.

How does an eBilling rules engine such as Onit detect block billing?

An eBilling rules engine such as Onit detects lumped entries by running configured checks against every line item when an invoice arrives and flagging lines whose narrative, hours, or codes match a lumping pattern. Your team defines those patterns during configuration.

• Task separators. Flag a narrative containing two or more semicolons, or three or more action verbs such as review, draft, call, and revise.
• Hours threshold. Flag any single line above 3 to 4 hours for a closer look.
• Daily maximum. Flag a timekeeper whose total hours on one date exceed a cap, such as 10 or 12 hours, which often surfaces lumped days.
• Code mismatch. Flag one task code next to a narrative describing several phases.

In our implementations, guideline rules such as daily maximum hours and line-item rate checks run at invoice validation, and flagged invoices route into a reviewer queue where the firm can see the reason and appeal. Lumping checks belong in the same rule set, next to the other guideline provisions that Onit billing rules can enforce.

Expect false positives, since a full-day deposition can legitimately run eight hours on one line. Run new rules as warnings for 30 to 60 days and tighten the thresholds before any rule reduces an invoice. These checks are configured alongside the rest of the Onit eBilling build, where validation rules, reviewer routing, and firm onboarding are set up together.

Should block-billed entries be rejected, reduced or sent back?

Block-billed entries should usually be sent back to the firm to resubmit with time split by task, with a fixed reduction for repeat cases and outright rejection for invoices that ignore a clear, communicated rule.

• Send back. For a first occurrence, return the line with a reason code. The firm keeps the fees it can justify, and you get usable data.
• Reduce. For a firm that keeps lumping after warnings, apply the reduction your guidelines state, typically 10 to 20 percent of the line.
• Reject. Reserve it for invoices where most lines are lumped, or after two or three requests to correct the same issue.

Write the response into the guidelines and apply it to every firm alike. Give firms an appeal window, such as 10 business days, and track how many appeals succeed. The reviewer queues that route flagged invoices in Onit carry those reason codes back to the firm. A high success rate means your thresholds need adjusting.

How do you reduce block billing without damaging law firm relationships?

You reduce lumped billing without damaging law firm relationships by announcing the rule before enforcing it, warning before you penalize, and showing each firm its own numbers. Firms push back hardest on rules they first discover on a reduced invoice.

The pressure on firms is real. A 2026 analysis of billing data from about 400 law firms found that invoice rejection rates climbed from 11 percent to 18 percent in 2025 as clients automated their checks. Firms that feel ambushed tend to escalate to the general counsel.

• Give notice. Send the updated guideline with an effective date at least 30 days out and a correct example entry.
• Warn first. Run one or two billing cycles where lumped lines are flagged with no reduction.
• Share the data. Send each firm its quarterly share of flagged lines, so the conversation stays on facts.
• Fix the source. Lumping often comes from timekeepers writing a day summary at 7 p.m., and changing that habit works faster than penalties.

How do UTBMS task codes help prevent block billing?

UTBMS task codes help prevent lumping because each line carries one task code, so a timekeeper who codes accurately has to split work that belongs to different tasks.

The litigation code set groups task codes into five phases, L100 through L500, and activity codes such as A103 Draft/Revise describe what was done. In our implementations, task and activity codes are captured on each invoice line item and checked against the outside counsel guidelines during invoice validation. Three controls follow:

• Required codes. Reject any line that arrives without both a task code and an activity code.
• One code per line. Accept a single task code per line item.
• Phase checks. Flag narratives that mention work from a different phase than the code selected.

A firm can still put three deposition tasks under one L330 line, which is why line-level UTBMS validation works best combined with narrative checks in the same rule set.

Conclusion

Lumped time hides the one thing a reviewer needs, which is how long each task took. Define the rule in your guidelines, configure narrative, hours, and code checks in your rules engine, run them as warnings first, and respond in proportion: send back, then reduce, and reject only when the rule is clearly ignored. Share the numbers with your firms, and most will change how they record time within a few billing cycles.

Frequently asked questions

Why do billing guidelines prohibit block billing?

Billing guidelines prohibit it because a single total for several tasks hides how long each task took, so a reviewer cannot test whether the hours were reasonable.

What is the difference between block billing and task-based billing?

A lumped entry combines several tasks under one total. Task-based billing records each task on its own line with its own hours and UTBMS task code.

Can Onit flag block-billed entries automatically?

Onit can flag lumped entries automatically through rules configured in its eBilling rules engine, such as narrative separator checks, single-line hour thresholds, and daily maximum hours. Flagged lines route to a reviewer queue for a decision.

Should block-billed entries be rejected or reduced?

Most departments send a first lumped entry back for resubmission, apply a stated percentage reduction to repeat cases, and reject only invoices that ignore a communicated rule.

How do UTBMS codes help prevent block billing?

UTBMS codes allow one task code per line, so accurate coding pushes timekeepers to split mixed work. Requiring task and activity codes on every line makes lumped entries easier to spot.

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*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.*