Billing and invoicing for security services

You can hold every contract in the market and still go under. Payroll runs on a fixed date. Client payments do not. Almost every collection problem you will have started as a billing problem three weeks earlier.

Which contract terms decide whether you get paid?

The dispute you will have in month eight is created by the vagueness you accepted in month one. Nail these down before signature.

• Bill rates, per position, per site, per shift. One blanket rate guarantees an argument the first time you send a supervisor to a post.
• Overtime rate. Often 1.5 times the regular bill rate, but it is negotiable and it has to be written down.
• Holiday rate, with the holiday list attached. "Holidays bill at premium" without a list means the client's list, not yours.
• Minimum hours per call-out. Without one, a three-hour emergency post costs you more than it earns.
• Billing frequency. Weekly, biweekly or monthly. This is your cash cycle, so treat it as a price term.
• Payment terms. Net 15 or Net 30 are the usual asks.
• Late payment interest. Rarely collected, frequently useful. It is what you point at on day 45.

Then pick a rate structure that matches how the service actually behaves. Hourly for variable coverage. Fixed monthly for a static post, which is predictable revenue but punishing if you estimated wrong. A base fee plus hourly above a threshold when volume swings. Per-patrol for a mobile route with a defined scope.

Whichever you pick, the number has to start from your loaded cost, not from what the incumbent charges. Setting your hourly bill rate works that calculation, and what belongs in a guard service agreement covers the clauses around it.

Why does time capture decide the invoice?

Wrong hours produce wrong invoices, and a wrong invoice does not get paid. It gets queried, and then it sits.

Five things have to be right on every shift before it is billable:

1. Clock-in and clock-out times that reflect what happened, not what was scheduled.
2. Site assignment mapped to the right contract, because the rate lives on the contract.
3. The correct rate code, so premium hours do not bill at straight time.
4. Overtime identified as overtime, at the point it happens.
5. A supervisor signature confirming the recorded hours match the work.

When the time system feeds the billing system directly, the retyping step disappears and so do most of the errors that come with it. Rates apply themselves. Exceptions get flagged for review before an invoice is cut rather than after a client finds them. If your clock-in data is coming off a paper sheet or a text message, that is the first thing to fix, and the payroll process needs the same data anyway.

What does an invoice need to survive AP?

Accounts payable departments reject on formatting more often than on substance. Give them nothing to reject.

Federal work sets a useful floor here. Under FAR 52.232-25 the government pays within 30 days of a proper invoice, and the clause spells out ten things that make an invoice proper, down to a named contact for defective invoices. If you bill federal, the Treasury prompt payment rules also owe you interest when they miss. Commercial clients owe you none of that, which is exactly why the invoice has to be clean.

Timing beats everything else on this list. Invoice the day the period closes, or the next business day. A week of internal delay is a week of delayed cash you never get back, and it happens quietly, every cycle.

Also: who receives the invoice and who approves it are usually two different people. Find out which is which at kickoff, while everyone still likes you.

How should you work the receivables?

Nobody pays faster because you waited politely.

Age invoices from the due date rather than the invoice date, or a Net 30 account looks delinquent on day 31 of a perfectly normal cycle. Review the aging weekly. Track Days Sales Outstanding as the single number that tells you whether billing and collection are working, and watch its direction more than its level.

Then run follow-up on a schedule that escalates on its own:

Phone beats email. Email is easy to ignore and impossible to negotiate with. On the call, get to the person who can release payment rather than the clerk who processes it, and find out the real reason: cash flow, a dispute, a lost invoice, or an approver on vacation. Each has a different fix. End every call with a specific date, write it down, and call back the day after it passes if nothing arrived.

What do you do when they dispute it?

Disputes are slow and they poison the relationship, so most of the work is upstream of them.

Four disputes account for nearly all of them. The client's hours do not match yours. The rate was not what they thought. Overtime was never authorized. Or the service quality complaint that surfaces for the first time on the day payment was due.

Prevention is mostly one habit: get client sign-off on hours before you invoice. That single step removes the largest category outright. Contract terms that leave no room for reading remove the second. Raising service problems when they happen, rather than letting them accumulate, removes the fourth, because a complaint saved up for the invoice is usually a payment tactic. Handling complaints as they happen is worth reading alongside this.

When one does land, move the same day. Send the supporting record: time detail, the DAR, the contract clause. Negotiate the disputed portion in good faith, and insist the rest of the invoice pays on time. A $400 argument should never hold up $18,000.

How do you survive the gap between payroll and payment?

This is the structural problem underneath everything above. You pay guards weekly or biweekly on a date you do not control, and you collect on a date the client controls.

Forecast against your actual collection timing rather than your terms, because those are different numbers and you already know it. Where you can, set payroll dates to land after expected collections. Keep a credit line open before you need it, since the moment you need it is the worst moment to apply. Offer an early-payment discount only if the discount costs less than the borrowing.

And treat the chronic late payer as a pricing question. A client at 60 days is financing itself with your money. Either the rate reflects that, the terms change, or the account is not worth keeping. Which is a different conversation from the one in keeping the clients you already have, and both are worth having.