The 2nd of the month, at your ESN (IT services company). Your admin team chases consultants one by one who haven't submitted their timesheet. The client contact who needs to validate it is travelling. Result: the timesheet goes out 10 days late, the invoice slips by a month, and your cash flow absorbs the gap.
The rule is brutal: no validated timesheet, no invoice. This document that everyone treats as an administrative formality actually conditions your entire revenue chain. Timesheet software exists for exactly this reason: turning the month-end scramble into an automatic flow, from data entry to cash collection.
Key takeaways
- The timesheet (compte rendu d'activité, or CRA) is the monthly document by which a consultant declares their worked days. Validated by the manager then the client, it serves as proof of service delivered and triggers time-and-materials billing.
- The rule that costs you money: no validated timesheet, no invoice. Every day of delay on a validation is a day of delay on cash collection.
- On spreadsheets, 4 systematic problems: manual chasing by the admin team, invoices that slip, double data entry that creates errors, and disputes you cannot settle for lack of timestamped proof.
- Effective timesheet software covers the full cycle: pre-filled entry, manager validation, client e-signature with no account to create, then invoices generated automatically from validated days × day rate.
- With mandatory e-invoicing (French regulation, effective 1 September 2026), an accurate invoice depends on accurate source data: the timesheet becomes a compliance issue, not just a cash-flow one.
What is timesheet software (compte rendu d'activité, or CRA)?
Timesheet software digitises the full activity-report cycle: consultants log their worked days, a manager then a client validate them, and the invoice is generated from the validated days. It replaces three things: the spreadsheet emailed back and forth, the manual month-end chasing, and the double entry between time tracking and the billing tool.
In an ESN, the timesheet plays 3 roles, which is what makes it critical:
- Proof of service delivered. Your client's admin team will require it before paying. Without it, the engagement isn't justified.
- Billing basis. In time-and-materials engagements, the invoice is calculated directly from validated days multiplied by the day rate.
- Management tool. It feeds utilisation rate, per-assignment profitability and month-end forecasting.
Be careful not to confuse it with a simple time-tracking sheet. Time tracking is a declaration; the timesheet is the consolidated, validated and legally opposable document that results from it. That evidentiary value is what matters the day a client disputes a billed day. An internal time-tracking sheet is worthless in a dispute; a signed, timestamped timesheet is not.
That is also why ESN timesheet software cannot be limited to a data-entry grid. It must manage the real validation chain (manager, then client), track who validated what and when, and above all automatically feed validated days into billing. Without that last link, you've just digitised the spreadsheet.
Timesheets on spreadsheets: what the month-end scramble really costs
Excel has one advantage: it looks free. Everything else is a hidden cost. In an ESN, managing timesheets on a spreadsheet systematically produces the same 4 problems.
1. The admin team spends month-end chasing people
In the last 3 days of the month, someone on your team sends out templates, chases latecomers individually, then chases the validator on the client side. On average, a significant share of consultants submit late, and every reminder is pure, non-billable administrative time. In a 50-consultant ESN, this ritual easily consumes 2 to 3 person-days per month — the equivalent of a third of a full-time role over a year — to produce data your consultants have already entered once.
2. The invoice slips, cash flow suffers
This is the most damaging cost, and the most invisible. A timesheet validated 10 days late means an invoice issued 10 days later, and therefore a payment collected 10 days later. Multiply that by your number of consultants and by 12 months: the gap adds up to tens of thousands of euros in working-capital needs. You are financing your client's cash flow with your own, without ever deciding to.
3. Double data entry creates errors
Validated days are copied by hand from the spreadsheet into the billing tool. Every re-entry is a chance to get it wrong: an outdated day rate, a missed day, a day booked to the wrong assignment. The result: credit notes to issue the following month, disputed invoices, and real margin you only find out about after the fact.
4. The dispute you cannot settle
Which version of the file did the client actually validate? Was the timesheet changed after they approved it? Without a timestamp or signature, you have no proof. The day a client disputes 4 billed days, a spreadsheet is worth nothing. An e-signed timesheet with an audit trail settles the debate in 10 seconds.
These 4 problems share a single root cause: the timesheet lives in an isolated file, disconnected from staffing upstream and billing downstream. As long as it stays a detached piece, it generates work instead of removing it.
The right timesheet flow: data entered once, used everywhere
The principle is easy to state, rarer to find in actual tools: a worked day should be entered once, then flow on its own all the way to the invoice. No email, no intermediate spreadsheet, no re-entry in accounting. Here's what that cycle looks like at the ESNs (IT staffing firms) that use Marvin, in 4 steps.
1. The consultant enters data on an already pre-filled base
The assignment already exists in the system: client, day rate, duration, working days. So the consultant doesn't open a blank sheet — they validate or correct a pre-filled timesheet from their assignment, in their consultant portal. Annual working days are calculated automatically, absences and expense reports come through on their own. Data entry takes 2 minutes, not 20.
2. The manager validates internally
The timesheet goes up to the manager, who checks it against the staffed assignment. Any anomaly (a day booked to the wrong assignment, unplanned overtime) is caught before the document reaches the client. This is the filter that prevents disputes, not the one that creates them.
3. The client validates and e-signs, with no account to create
This is the classic blocking point: the client validator has no interest in learning a new tool. With us, they receive the timesheet, validate it and e-sign it in one click, with no account to create. Every validation is timestamped and tracked with its audit trail. You get what neither Excel nor a PDF will ever give you: legally opposable proof of service delivered.
4. The invoice is generated from the validated timesheet
As soon as the timesheet is signed, Cash generates the client invoice from validated days multiplied by the day rate. The consultant's pay statement is generated in mirror. No re-entry, no possible gap between what was validated and what is billed. And because the sell-side and buy-side day rates live in the same system, gross margin is displayed assignment by assignment, consolidated by business unit, in real time.
Upstream, Desk created the assignment from the commercial pipeline, and People keeps the consultant pool up to date: real-time availability, assignment history, upcoming assignment end dates. The timesheet is therefore not an isolated document — it's the last link in a chain that starts at staffing and ends at cash collection.
This is exactly what our clients tell us:
"We replaced 4 tools with Marvin. The path from timesheet to invoice, which used to take 3 days, is now instant."
ESN with 80 consultants, Paris region
At a glance, here's what changes:
| Timesheets on Excel | Automated timesheets with Marvin | |
|---|---|---|
| Consultant entry | Blank sheet, sent by email | Pre-filled from the staffed assignment |
| Reminders | Manual, from the admin team, every month | Automatic, no one chases anyone anymore |
| Client validation | Email, PDF, sometimes paper | E-signature in 1 click, no account to create |
| Proof in a dispute | None (which version?) | Timestamped audit trail |
| Billing | Manual re-entry of days | Generated automatically from the validated timesheet |
| Margin per assignment | Calculated after the fact on a spreadsheet | Visible in real time (sell-side vs buy-side day rate) |
| Invoice delay | Delayed by 1 to 3 weeks | Issued as soon as the timesheet is signed |
The gain isn't just administrative, it's financial. Our clients replace an average of 5 to 7 tools with a single platform and free up around 7 hours per week per consultant. And above all, they bill sooner.
What mandatory e-invoicing changes for your timesheets
This deadline is close and it concerns every ESN operating under French tax rules. Under French regulation, from 1 September 2026 all companies subject to VAT must be able to receive electronic invoices, and large companies and mid-caps are required to issue them. SMEs and micro-businesses follow on 1 September 2027.
In practice, a PDF sent by email will no longer be a valid invoice between businesses. A structured invoice (Factur-X, UBL, CII) must be transmitted via an authorised platform. And a structured invoice, by definition, does not tolerate approximation: the number of days, the day rate, the assignment reference, the client's company registration number — everything must be accurate and machine-readable.
This is where the timesheet becomes central again. An accurate invoice depends on accurate source data. If your billed days are copied by hand from a spreadsheet, you inject your data-entry errors directly into a now-automated tax pipeline, with penalties attached for non-compliant invoices. Conversely, when the invoice is generated from a validated, e-signed timesheet, the data is accurate by construction.
The reform is therefore not just a compliance constraint: it's a good excuse to eliminate re-entry between the timesheet and billing, once and for all.
Marvin versus BoondManager and ConnectingExpertise
When an ESN looks to tool up its timesheet process, two names come up regularly. Here's what they bring, and what sets us apart.
BoondManager is the sector's long-standing ERP. What it does better: mature, proven ERP coverage, with timesheet management refined over more than 15 years and a solid ecosystem of accounting connectors.
ConnectingExpertise plays on different ground: VMS (Vendor Management System). What it does better: managing suppliers and subcontracting at scale, for buyers overseeing dozens of service providers. A real need, but one that answers a buyer's problem more than an ESN's.
The difference, with us, comes down to one sentence: the timesheet isn't a module bolted onto the others — it shares the same data as the CRM, the consultant pool and billing. The assignment created by sales feeds the consultant's timesheet, which triggers the invoice, which displays the margin. Zero double entry, no connector to maintain between three separate building blocks.
On top of that, there's a generational difference: Marvin is a native-AI suite, designed from the ground up around semantic sourcing and autonomous agents, whereas legacy ERPs bolt AI on in successive layers. For an ESN that recruits as much as it staffs, this continuity between sourcing, staffing and timesheets changes day-to-day operations.
We break this comparison down feature by feature in our dedicated analysis: Marvin vs BoondManager.
The timesheet isn't an administrative chore, it's your cash flow
Back to the opening question. The timesheet really is the link that decides your cash flow: as long as it isn't validated and signed, your revenue remains theoretical. Every day of delay on a validation is a day of delay on cash collection.
Good timesheet software doesn't just digitise the spreadsheet. It eliminates chasing, secures client validation with legally opposable proof, and generates the invoice directly from validated days, with no re-entry. That's what turns the month-end scramble into a flow that runs on its own, and brings cash in sooner.
That's exactly what we built for ESNs and consulting firms: a continuous chain, from staffing to cash collection, in a single platform built for IT staffing firms. If commercial pipeline management interests you too, we covered it in detail in our article on ESN CRM.
Want to see the flow run on your own assignments? Book a demo: we'll show you the complete journey in real conditions, from consultant entry to invoice sent, using your own use cases.
Frequently asked questions about timesheet software
What is a timesheet (CRA) in an ESN?
The timesheet (compte rendu d'activité, or CRA) is the document by which a consultant declares, every month, the days worked on each of their assignments, as well as their absences. Validated by the manager then the client, it serves as proof of service delivered and triggers billing for time-and-materials engagements. Without a validated timesheet, the invoice cannot go out: it's the piece that conditions an ESN's entire revenue chain.
Is a timesheet mandatory?
There's no general legal obligation requiring every company to produce a timesheet. However, it is contractually essential for time-and-materials engagements: it's the supporting document your client's admin team will require before paying. In umbrella employment (portage salarial), it's practically systematic, since it conditions both billing and salary calculation. In short: nothing forces you to produce one, but without it, you don't bill.
What's the difference between a timesheet (CRA) and a time-tracking sheet?
A time-tracking sheet is a declaration: the employee logs their hours or days there. The timesheet is the consolidated, validated and legally opposable document that results from it, with manager and client validation. That evidentiary value is what makes the difference: an internal time-tracking sheet is worthless against a client disputing a billed day, whereas an e-signed, timestamped timesheet settles the debate.
How does timesheet software speed up billing?
By eliminating the 3 steps that waste time: manually chasing consultants and the client validator, waiting for a signature by email, and re-entering days into the billing tool. When the invoice is generated automatically from the validated timesheet, it goes out the same day it's signed, not 2 weeks later. That's days gained on your working-capital needs.
Does the client need to create an account to validate the timesheet?
No, and that's a decisive point for adoption. A client-side validator has no interest in learning their provider's tool. With us, they receive the timesheet, review it and e-sign it in one click, with no account to create. The signature is timestamped and tracked with its audit trail, giving you usable proof in the event of a dispute.
Does timesheet software handle subcontractors?
This is a classic blind spot. In an ESN, subcontractors often represent a significant share of billed headcount, and if they log their time through a separate channel (email, PDF, client portal), you end up reconciling two systems, with the gaps that come with it between the validated timesheet and the supplier invoice received. Good timesheet software has them enter data through the same channel as internal consultants, with the consultant's pay statement generated in mirror of the client invoice.
Does timesheet software replace an ESN ERP?
Timesheet software alone does not: it handles time tracking and validation. An ESN ERP covers the whole chain, from staffing to billing. The real question isn't choosing between the two, but avoiding breaks between them. At Marvin, the timesheet, the consultant pool, the CRM and billing share the same data — so there's no connector to maintain between time tracking and the rest of the system.
