How to bill a client for manpower: staff-days, OT and GST

What is a staff-day, and why bill by it?

A staff-day is one staff member on duty for one day. Five staff each working 26 days is 130 staff-days. Billing by staff-day means the bill follows attendance exactly. If a post was left empty for two days, the client pays for two fewer staff-days, and you have the attendance to show why.

Some contracts are priced as a monthly rate per post instead. That works too: the bill is posts × monthly rate, with a deduction for days a post was not covered. Either way, the bill is only as good as the attendance behind it.

How do you build the bill step by step?

1. Close attendance for the month, site by site, and get the client's site in-charge to sign the sheet if your contract asks for it.
2. Count staff-days per category (for example day-shift security, night-shift security, housekeeping). A half-day is 0.5.
3. Multiply by the agreed rate for each category.
4. Add overtime only if the contract bills it, as hours × the agreed hourly rate.
5. Work out GST on the total (the taxable value).
6. Issue a tax invoice and attach the attendance summary.

Worked example: one site, three categories

If the client were in another state, the ₹35,438.40 of tax would be shown as IGST at 18% instead. The site billing calculator works this out for one line, and the manpower bill format handles several lines with CGST, SGST and IGST in Excel.

How does GST work on a manpower bill?

Security services and manpower supply are taxed at 18% (9% CGST + 9% SGST, or 18% IGST) under SAC 9985. The one twist is reverse charge: when a proprietor or partnership firm supplies security staff to a registered business, the client pays the GST directly and your bill shows none. Housekeeping and other manpower supply are not covered by that rule, so for them you charge GST yourself.

The exceptions, the notification wording, CGST vs IGST and a worked example are in our guide to GST on manpower and security services. Ask your CA which exact SAC code fits your service.

HaazriPro works this out every month from your attendance, for every staff member and site. Start 30-day free trial  →

What must the invoice show?

A tax invoice must carry the particulars the GST rules list, including your GSTIN, invoice number and date, the client's details, place of supply, the service code, the taxable value and tax. Under section 31 of the CGST Act read with rule 46 of the CGST Rules, every tax invoice must also say whether tax is payable on reverse charge. It also helps a security agency to show its PSARA licence number on the invoice.

What should you attach to the bill?

Clients pay faster when they can check the bill against their own records without calling you. Attach:

• a staff-day summary per site, category and shift, matching the invoice lines;
• the attendance sheet for the month, signed by the client's site in-charge if the contract asks for it;
• an overtime statement with dates and hours, if you bill overtime;
• proof of statutory payments (PF and ESI challans, wage register) if your contract makes payment depend on them. Many principal employers ask for these every month.

How do you bill for a post that was left empty?

Bill only the staff-days actually worked. If a post was uncovered for a day, leave that staff-day out rather than waiting for the client to find it. Some contracts also set a penalty for uncovered posts; read the clause and apply it yourself. A bill that already reflects the gaps is far easier to defend than one the client has to correct.

How do you avoid billing disputes?

• Bill from attendance, not from the roster. Clients check. A bill that matches a signed attendance sheet is rarely questioned.
• Attach a staff-day summary per site and category.
• Agree overtime in writing before you bill it, with the hourly rate.
• Revise rates when wages change. When the state raises VDA, your cost goes up the same month. A revision clause in the contract lets your bill follow it. See how to calculate a rate per post.

Sources

• Notification 29/2018-Central Tax (Rate): reverse charge on security services
• Notification 11/2017-Central Tax (Rate): rates for services, heading 9985
• GST Council, 56th meeting: rate changes from 22 September 2025
• GST Council flyer: reverse charge mechanism (invoice must state reverse charge)

This guide explains the rules in plain language. It is not legal or tax advice. Laws and rates change, so confirm the GST treatment of your contracts with your CA before you act on it.