How to Invoice Clients from Approved Timesheets: Approvals, Period Locks and Write-offs

Short answer: Staff record time daily against an engagement, a manager approves it every week, the approved period is locked so hours can't change, rate rules value each hour (the most specific rule wins), and invoices are raised only from approved, unbilled, billable time, with each time entry linked to the invoice that billed it. Record every write-off with a reason, and measure realisation as amount invoiced over the standard value of the time.

Last updated 14 October 2026. This guide is vendor-neutral; where we mention MyPract, every claim comes from our facts page or the product itself.

Time-based billing breaks in the gap between the timesheet and the invoice. Hours sit unapproved for a quarter, someone edits last month's entries after the bill went out, the same hour carries three different rates, and the partner rewrites the invoice from memory. Each step below closes one of those gaps.

What does "invoice from approved timesheets" mean?

It means the invoice is built from records a manager has already checked, not from a partner's estimate. Every billable hour goes through the same five steps:

How should time approvals work?

Approve weekly. A manager reviewing last week's entries on Monday spends minutes; reviewing a quarter before invoicing takes days and turns doubts into write-offs. When approving, check four things:

• Engagement: is the time on the right client and engagement?
• Billable flag: is internal work, training or rework marked non-billable?
• Description: would it survive a fee query from the client?
• Hours against budget: is the engagement heading over its budget hours? If so, raise it with the partner now, not at billing.

Send entries back for correction rather than editing them yourself, so the person who did the work fixes the record.

What is a period lock, and when should you lock?

A period lock closes a date range so time inside it can't be created or edited. Lock after approval, and always after invoicing. Without a lock, someone can edit an hour that has already been billed, and your invoice, timesheet and utilisation report stop agreeing.

A workable rhythm: staff complete timesheets by Friday, managers approve by Monday, and the previous month locks a few working days into the next. If a genuine correction is needed later, unlock deliberately, fix it and relock, so the change is a decision, not an accident.

How do you set rate rules?

A rate rule says what an hour is worth. Keep the hierarchy simple and let the most specific rule win:

Give each rule an effective date. When rates change in April, last year's time should keep last year's value, or your realisation figures will be wrong.

How do you turn approved time into an invoice?

1. Pick the client, the engagement (or all of them) and the period.
2. Pull only approved, unbilled, billable entries in that range. Anything unapproved waits for the next run.
3. Group entries into readable lines, for example by engagement or by work type, with hours and rate.
4. Review the draft: compare the total with the standard value and with any fee agreed in advance. Adjust lines if you're writing off.
5. Issue the invoice and link the entries to it, so they can't be billed twice and a fee query can be traced from the invoice line to the hours.

For fixed-fee work, still record time. Invoice the agreed fee, and compare it with the standard value of the time to see whether the fee was right. That comparison sets next year's quote.

Timing. For GST-registered firms there's a legal clock too: rule 47 of the CGST Rules requires a tax invoice for a taxable service within 30 days of the date of supply.^[1] Weekly approvals make that easy to meet.

How should you handle write-offs?

A write-off is the difference between the standard value of the time and what you invoice. Don't hide it; record it with a reason.

Keep the reason with the invoice, in your own write-off log or an export, so that after a season you can see which cause costs the most.

How do you measure realisation?

Billing realisation = amount invoiced ÷ standard value of the billable time behind it.

An illustration with made-up numbers: an engagement has 50 approved billable hours at a rate of ₹1,200, so a standard value of ₹60,000. The invoice is for ₹51,000. Billing realisation is 85%, and ₹9,000 was written off.

Collection realisation (amount collected ÷ amount invoiced) is the second half, and it depends on your follow-up, not your timesheets. Set targets from your own history rather than borrowed benchmarks. Our guide to tracking billable hours explains utilisation and realisation side by side.

How does MyPract do it?

In MyPract, staff record time in a weekly timesheet or with a start-stop timer, billable or non-billable, against clients and engagements. Managers approve time and lock past periods; time inside a locked period can't be created or edited. Rate rules can be set for the workspace, a member, a client or an engagement, with optional effective dates, and the more specific rule wins over the workspace default.

To bill, a manager chooses a client, optionally one engagement, and a date range, and MyPract groups the approved, unbilled time entries in that range into line items on a new draft invoice. The draft's lines can be edited before it's issued, and the time entries are linked to the invoice. Invoices are numbered INV-YYYY-NNNN and move through Draft, Sent, Paid, Overdue and Void; each client can be invoiced in its own currency, and invoices print or save as PDF. Reports cover utilisation against each person's weekly capacity and engagement burndown against budget hours, exportable to CSV.

What it doesn't do: MyPract does not collect payments or send payment links, so you mark an invoice paid when the money arrives. It doesn't send recurring invoices or payment reminders automatically, doesn't integrate with Tally or any accounting ledger, and doesn't report realisation, which you calculate from invoices and time exports. See pricing, our time tracking and billing software roundup and the best practice management software for CA firms for other options. If you're billing after a busy season, our tax audit season workflow covers the work that comes before.

How we checked

The approval, lock and rate-rule practices are standard professional-services billing practice; the realisation example uses made-up numbers, not benchmarks. We relied on CBIC's tax information portal for rule 47 of the CGST Rules, as checked on 13 October 2026 for our billable-hours guide. MyPract features come from our facts page, and the invoice-from-time and rate-rule details were checked in the product on 14 October 2026. No MyPract prices or exchange rates are used in this guide.

Frequently asked questions

Why invoice only from approved time?

Because approval is where errors get caught cheaply, such as the wrong client, a billable flag on internal work or a vague description. Billing unapproved time moves those errors onto the invoice, where they become fee disputes and write-offs.

What is a period lock on timesheets?

A lock on a date range so time in it can't be created or edited. Firms lock a period once it's approved or invoiced, so the timesheet, the invoice and the reports keep agreeing.

How do rate rules work when several apply?

The most specific rule should win. A rate agreed for an engagement beats the client's rate, which beats the person's rate, which beats the firm's default. Date each rule so old time keeps its old value.

How do you calculate billing realisation?

Divide the amount invoiced by the standard value of the billable time behind it (hours times rate). If approved time worth 100 is invoiced at 85, realisation is 85% and 15 was written off.

Does MyPract collect payments or send recurring invoices?

No. MyPract creates invoices from approved, unbilled, billable time and tracks their status, but it doesn't collect payments, send payment links, send recurring invoices automatically or email payment reminders. You mark an invoice paid when the money arrives.

Bill from approved time with MyPract

Timesheets, weekly approvals, period locks, rate rules and invoices built from approved hours, in one workspace. Three months free, no card, and the trial never converts automatically.

Sources

[1] Central Board of Indirect Taxes and Customs, "CGST Rules, 2017: Rule 47, Time limit for issuing tax invoice" (checked 13 October 2026).