From Project Time to Customer Invoice: A Simple Billing Workflow

For many service businesses, preparing an invoice begins with a familiar question:

What work did we complete, and what should we charge the customer?

The answer may be spread across employee timesheets, project notes, job records, photos, forms, product lists, and messages. A manager then has to reconstruct the work before creating the invoice.

This process takes time and increases the risk of missing billable hours, charging the wrong rate, billing the same work twice, or sending an invoice before the work has been reviewed.

A connected billing workflow creates a clearer path:

Completed work → Submitted time → Manager approval → Invoice preparation → Customer payment

The employee records what happened. The manager reviews the work. Approved billable time and other authorized charges become the source for preparing the customer invoice.

Why approved time should be the source of hourly billing

Employees often have the most accurate information about when project work started, stopped, and changed. However, a submitted time log should not automatically become a customer charge.

Time may need review because:

• The employee selected the wrong project or job
• The timer was left running
• A break was not recorded
• Part of the time was non-billable
• The customer approved only part of the work
• A fixed-price agreement already covers the labour
• Travel time follows a different billing rule
• The job uses a special customer rate
• Two employees recorded overlapping work
• The time belongs to warranty or rework

A manager-approval step creates a clear boundary between employee-reported time and business-approved billing information.

The employee records what happened. The manager determines whether the record is accurate, payable to the employee, billable to the customer, or both.

Once approved, the time becomes a more reliable source for invoice preparation.

Payable time and billable time are different

A common billing mistake is assuming that every paid employee hour can be charged to a customer.

These are separate decisions:

• Payable time affects employee gross earnings.
• Billable time affects the customer invoice.

An employee may need to be paid for time that the business cannot bill to the customer.

Examples include:

• Internal meetings
• Training
• Rework
• Administrative work
• Unapproved travel
• Warranty service
• Time exceeding a fixed-price agreement

The reverse may also occur. A customer invoice may contain a fixed service charge, product, or quantity-based item that does not come directly from employee hours.

Keeping payable and billable decisions separate gives managers a more accurate view of employee earnings, project cost, customer billing, and project profitability.

Review the work before preparing the invoice

Approved time is important, but it may not be the only evidence needed before billing.

A manager may also review:

• Completed jobs and tasks
• Submitted forms
• Before-and-after photos
• Customer signatures
• GPS information
• Equipment scans
• Completion notes
• Customer-approved changes
• Products or materials used
• Fixed-price services
• Quantities delivered
• Previous invoices for the project

This review helps answer three questions:

1. Was the work completed?
2. Is the charge supported by the project record?
3. Has any part of the work already been invoiced?

The purpose is not to make every invoice difficult to create. It is to give the business a consistent review point before customer-facing financial records are produced.

Use project default rates for standard work

A project can have a default customer bill rate for standard hourly work.

For example:

• Standard maintenance project: $65 per hour
• Bookkeeping project: $55 per hour
• Consulting project: $120 per hour
• Cleaning project: $40 per hour

When an employee records billable time, the project’s default rate can be used to calculate the proposed billing value.

If four approved billable hours use a rate of $65 per hour, the proposed labour charge is:

4 hours × $65 = $260

A default rate reduces repeated data entry and helps the business apply consistent pricing.

However, it should remain a default rather than an irreversible value. Managers need to review whether the rate is appropriate for the specific work.

Use job-specific rate overrides when necessary

Not every job within a project uses the same customer bill rate.

A job-specific override may be appropriate for:

• Emergency work
• After-hours service
• Weekend service
• Specialized labour
• Senior consultant work
• Travel time
• Warranty work
• Discounted work
• Work performed under a separate agreement

For example, a maintenance project may use a standard rate of $65 per hour, while an emergency repair job uses $95 per hour.

The project supplies the normal rate. The job supplies the exception.

This keeps the pricing structure manageable. Managers do not need to create a separate project for every rate, and employees do not need to decide which rate applies while recording their time.

The system should preserve the rate used when the time is approved or added to an invoice. Changing the project’s current default rate should not silently change an invoice that has already been issued.

Keep employee wage rates separate from customer bill rates

The employee wage rate and customer bill rate serve different purposes.

For example:

• Employee wage rate: $25 per hour
• Customer bill rate: $65 per hour
• Approved time: 4 hours

The employee’s gross earnings may be based on:

4 hours × $25 = $100

The proposed customer charge may be:

4 hours × $65 = $260

The difference is not automatically profit. The business may also need to cover:

• Employer payroll costs
• Benefits
• Insurance
• Travel
• Equipment
• Materials
• Administration
• Rent
• Software
• Other operating expenses

The two rates should remain separate. Customer invoices should not expose employee wage information, and employees should not require access to confidential customer pricing simply to record project time.

Choose the right invoice-line type

Not every customer charge should be calculated in the same way.

A practical invoice may contain hourly, fixed, quantity-based, service, and product line items.

Hourly line items

Hourly billing is appropriate when the customer pays for approved working time.

An hourly line may contain:

• Description
• Project or job
• Number of approved hours
• Customer bill rate
• Amount
• Tax treatment

For example:

HVAC inspection labour — 4 hours × $65 per hour

Hourly lines may be created from one time log or several approved time logs.

Fixed line items

A fixed line is appropriate when the customer agreed to a defined price regardless of the exact number of hours used.

Examples include:

• Monthly cleaning service
• Website assessment
• Equipment installation
• Standard inspection
• Bookkeeping package
• Call-out charge

For example:

Monthly bookkeeping service — $750

The business should still record employee time for labour cost and project reporting, even when the customer pays a fixed amount.

This allows managers to compare the fixed price with the actual work required.

Quantity-based line items

Quantity billing is useful when the price depends on the number of units delivered or completed.

Examples include:

• 12 windows cleaned
• 5 devices installed
• 20 filters replaced
• 3 rooms serviced
• 150 printed labels
• 8 equipment inspections

For example:

Replacement air filters — 8 × $25

The quantity may come from a job record, completion form, employee report, or manager confirmation.

Service line items

A service line represents a defined service from the business’s product and service catalogue.

Examples include:

• Standard service call
• Annual inspection
• Consultation
• Deep cleaning
• Installation service
• Monthly bookkeeping
• Emergency response

A service may have a default description, price, unit, and tax setting. The manager can add the service to the invoice and adjust it when the customer agreement requires something different.

Product line items

Products may be added when materials, parts, or physical items are charged to the customer.

Examples include:

• Replacement component
• Air filter
• Cleaning supply
• Cable
• Sensor
• Printed report
• Equipment accessory

The invoice may show the product description, quantity, unit price, amount, and applicable tax.

NuvoTime can use products and services to support customer invoice preparation. It is not intended to replace a complete purchasing, warehouse, or inventory-accounting system.

Combine different line types on one invoice

A customer invoice may contain several billing methods.

For example:

Description	Type	Quantity	Rate	Amount
Emergency repair labour	Hourly	3 hours	$95	$285
Service call	Fixed service	1	$75	$75
Replacement valve	Product	1	$120	$120
Disposal fee	Fixed	1	$20	$20

The subtotal before tax is:

$285 + $75 + $120 + $20 = $500

This approach allows the invoice to reflect the real agreement with the customer instead of forcing every charge into hourly billing.

Convert approved time into invoice lines

Approved billable time should become available for invoice preparation.

A manager may choose to:

• Create one line for each time log
• Group time by employee
• Group time by job
• Group time by service
• Combine all approved hours into one labour line
• Exclude selected records
• Split one time log between billable and non-billable portions
• Change the customer-facing description

For example, three employees may record:

• Employee A: 2 hours
• Employee B: 1.5 hours
• Employee C: 2.5 hours

The invoice could show three separate lines, or it could show:

Installation labour — 6 hours × $65 per hour

The internal records should still preserve who performed the work, even when the customer sees one combined line.

Prevent approved time from being billed twice

Once approved time has been added to an invoice, the relationship should remain visible.

The time record may be identified as:

• Available to invoice
• Added to a draft invoice
• Invoiced
• Removed from an invoice
• Written off or excluded

This helps managers see which approved hours remain unbilled.

If a draft invoice is deleted or a time-based line is removed, the related time can become available again when appropriate.

The goal is to prevent two common problems:

• Missing approved time that should have been billed
• Adding the same approved time to more than one invoice

A clear connection between time logs and invoice lines supports a reliable audit history.

Keep invoice lines editable

Approved time should be the source of billing information, but it should not make the invoice impossible to edit.

A manager may need to change:

• Customer-facing description
• Quantity
• Rate
• Discount
• Tax treatment
• Service date
• Line order
• Grouping
• Internal note
• Invoice note

For example, an employee’s internal note may say:

Replaced failed valve after inspecting pressure issue.

The customer-facing invoice line may say:

Diagnostic and valve-replacement labour — 3 hours

Editing the description makes the invoice easier for the customer to understand without changing the employee’s original time record.

If a manager changes the quantity or rate, the invoice should preserve the final amount used. The source time record should remain available for comparison.

Avoid changing the original time record to match the invoice

The employee’s time record and the invoice line are related, but they are not the same record.

Suppose an employee worked four hours on a fixed-price job. The customer may be billed $500 regardless of the number of hours.

The time record should continue to show four approved hours. The invoice should show the agreed fixed amount.

Changing the time entry to make it resemble the invoice would reduce the accuracy of labour-cost and project-performance reporting.

Preserve the operational facts, then apply the correct customer billing method.

Set the invoice currency

Each invoice should have a clear currency.

Examples include:

• CAD
• USD
• EUR
• GBP

The currency should normally come from the customer, project, or business settings. Managers should verify it before issuing the invoice, especially when the business serves customers in more than one country.

Once an invoice has been issued, changing its currency can affect prices, taxes, payments, and financial reporting. A correction or replacement invoice may be more appropriate than directly changing an issued invoice.

NuvoTime can record invoice amounts and currencies. Currency conversion, foreign-exchange gains or losses, and formal multi-currency accounting may still need to be completed in accounting software.

Configure sales-tax settings

Sales-tax rules depend on the business location, customer location, type of product or service, registration status, and applicable law.

Depending on the jurisdiction, a business may need to handle taxes such as:

• GST
• HST
• PST
• QST
• VAT
• Other regional sales taxes

The business should configure its applicable tax names and rates instead of requiring employees to choose taxes while recording project time.

Tax settings may be applied from:

• Business defaults
• Customer settings
• Product or service settings
• Invoice-line settings
• A specific tax exemption

For example, a taxable service invoice may calculate:

• Subtotal: $500
• GST at 5%: $25
• Total: $525

Some invoice lines may use different tax treatment. A product may be taxable while another service is exempt or zero-rated, depending on the applicable rules.

Managers should review tax settings before issuing the invoice. Software can calculate using the configured rules, but the business remains responsible for determining the correct tax treatment.

Distinguish tax-inclusive and tax-exclusive pricing

A business should decide whether entered prices include or exclude sales tax.

With tax-exclusive pricing, tax is added to the subtotal.

For example:

• Service price: $100
• GST at 5%: $5
• Invoice total: $105

With tax-inclusive pricing, the displayed amount already contains the tax.

For example:

• Tax-inclusive total: $105
• Included GST: $5
• Before-tax amount: $100

The invoice should clearly communicate the method used. Mixing inclusive and exclusive pricing without clear rules can produce confusing totals and inaccurate tax summaries.

Use clear invoice statuses

An invoice status helps the business understand where each invoice is in the billing process.

A practical status flow may include:

• Draft
• Issued or Sent
• Partially Paid
• Paid
• Overdue
• Void

Draft

The invoice is still being prepared. Lines, descriptions, rates, and tax settings can be reviewed before the customer receives it.

Issued or Sent

The invoice has been finalized and provided to the customer. The invoice number, issue date, currency, totals, and tax amounts should now be treated as an official business record.

Partially Paid

The customer has made a payment, but an outstanding balance remains.

Paid

Recorded payments equal the amount due.

Overdue

The invoice has an unpaid balance after its due date.

Void

The invoice is no longer payable but remains in the history. Voiding is generally safer than deleting an invoice that has already been issued.

The exact terminology may differ by business, but the status should be clear to managers and consistent in reports.

Record customer payments

An invoice and a payment are different records.

The invoice says what the customer owes. A payment records money received against that invoice.

A payment record may include:

• Invoice
• Customer
• Payment date
• Amount
• Payment method
• Reference number
• Note
• Recorded by
• Currency

A customer may pay:

• The full invoice
• Part of the invoice
• Several invoices together
• More than the amount due
• Through several payment methods

For a simple workflow, each payment can be applied to the appropriate invoice and reduce its outstanding balance.

For example:

• Invoice total: $525
• First payment: $300
• Remaining balance: $225
• Status: Partially Paid

After the remaining $225 is recorded, the status becomes Paid.

Recording a payment in NuvoTime helps the operational team track invoice status. It does not confirm that the payment has cleared the bank unless the business separately verifies it.

Do not rewrite issued invoices after payment

Once an invoice has been issued or paid, changes should be handled carefully.

Directly changing the amount can create differences between:

• The invoice sent to the customer
• The payment received
• The tax recorded
• The accounting record
• The invoice stored in the business history

Depending on the situation and local requirements, the business may need to void the invoice, issue a corrected invoice, or create a credit or adjustment in its accounting system.

NuvoTime should preserve the operational history. The business should follow the appropriate accounting and tax process for formal corrections.

Track sales tax collected

When a taxable invoice is issued and paid, the business may collect sales tax on behalf of a government authority.

That amount is not ordinary business revenue.

A sales-tax summary may show:

• Taxable sales
• Non-taxable or exempt sales
• Tax collected by tax type
• Tax collected by reporting period
• Adjustments or voided invoices
• Payments connected to taxable invoices

For example:

Tax type	Taxable sales	Tax collected
GST 5%	$10,000	$500
PST 7%	$4,000	$280

This gives the business a practical summary of customer invoices and recorded tax amounts.

The report should clearly state whether it is based on invoice dates, payment dates, or another configured basis. Accounting and tax reporting may use accrual, cash, or other required methods depending on the business and jurisdiction.

Use remittance summaries as preparation information

A remittance summary can help the business prepare for sales-tax filing by organizing:

• Tax collected
• Taxable sales
• Exempt or zero-rated sales
• Adjustments
• Reporting period
• Related invoices and payments

However, sales tax payable is not always equal to the total tax collected.

The business may be entitled to credits for eligible tax paid on purchases, such as Canadian input tax credits for GST/HST registrants. Those purchase-side amounts may be maintained in accounting software rather than NuvoTime.

For this reason, NuvoTime’s sales-tax summary should be treated as supporting information, not the final government return.

The business or its accounting professional should confirm:

• Filing frequency
• Reporting basis
• Eligible credits
• Adjustments
• Amount payable or refundable
• Filing deadline
• Government submission

NuvoTime can summarize the invoice-side information it records. It does not file or remit sales tax automatically unless a separate feature explicitly provides that service.

Generate a clear invoice PDF

The invoice PDF is the customer-facing record.

It should clearly show:

• Business name and contact information
• Customer name and billing address
• Invoice number
• Issue date
• Due date
• Currency
• Line-item descriptions
• Quantities
• Rates
• Subtotal
• Discounts, when applicable
• Sales-tax names, rates, and amounts
• Total
• Payments already recorded, when applicable
• Balance due
• Payment instructions
• Customer or project reference

The customer should be able to understand the invoice without seeing internal timesheets, wage rates, manager notes, or private employee information.

A clear invoice reduces customer questions and makes payment easier.

Email invoice PDFs from the business’s address

Invoices should normally be sent using the business’s approved email identity.

Examples include:

• billing@example.com
• accounts@example.com
• hello@example.com

The message can include:

• Customer name
• Invoice number
• Invoice amount
• Due date
• Short payment instructions
• Contact information for questions
• The invoice PDF

For example:

Hello Maria,

Please find attached invoice INV-1048 for the September maintenance work. The total is $525 and payment is due on October 15.

Please contact us if you have any questions.

The system should record that the invoice email was sent and identify delivery problems when they occur.

Sending an email does not guarantee that the customer received, opened, or accepted the invoice. Businesses should follow up on delivery failures and overdue balances.

Keep internal details out of the customer invoice

The business may need detailed internal information for review, but the customer invoice should remain clear and professional.

Internal records may contain:

• Employee wage rates
• Internal cost estimates
• Manager comments
• Approval history
• GPS information
• Private employee notes
• Profitability calculations
• Internal dispute details

These details should not appear on the customer-facing invoice unless there is a specific reason.

The invoice should explain what the customer is being charged, not expose every internal step used to calculate it.

A simple project-to-invoice workflow

A practical billing process can follow these steps:

1. Employees record time against the correct project and optional job.
2. Employees submit required notes, photos, forms, and other evidence.
3. Managers review project time and completed work.
4. Managers approve payable and billable time separately.
5. Approved billable time becomes available for invoice preparation.
6. Project default rates or job-specific overrides provide the proposed hourly rates.
7. Managers add fixed, quantity, service, and product lines when needed.
8. Managers review descriptions, quantities, rates, currency, and sales tax.
9. The invoice remains a draft until the review is complete.
10. The invoice is issued and emailed to the customer as a PDF.
11. Customer payments are recorded against the invoice.
12. Invoice and tax summaries support later accounting review.

This process keeps the employee workflow simple while giving managers control over customer billing.

Common billing mistakes to avoid

Billing submitted time before approval

Submitted time may contain mistakes or non-billable work.

Use approved billable time as the source for invoice preparation.

Treating every employee hour as billable

An employee may need to be paid even when the customer cannot be charged.

Keep payable and billable time separate.

Using one rate for every job

Emergency, specialized, after-hours, or discounted work may require a job-specific rate.

Use the project rate as a default and override it only when necessary.

Changing time records to match fixed-price invoices

The time record should show the work performed. The invoice should show the agreed charge.

Preserve both records accurately.

Billing the same time twice

Connect invoice lines to their source time logs and identify which records have already been invoiced.

Hiding important charges in vague descriptions

A customer should understand what the invoice covers.

Use clear descriptions without exposing unnecessary internal details.

Letting employees choose sales-tax treatment

Sales tax is a business and accounting decision.

Apply configured customer, product, service, and invoice rules during invoice review.

Deleting issued invoices

Issued invoices form part of the business history.

Use controlled voiding or correction processes when appropriate.

Treating tax collected as revenue

Sales tax collected may be owed to a government authority.

Track it separately and review it during remittance preparation.

Assuming a payment record confirms bank settlement

A recorded payment supports invoice tracking, but the business may still need to verify that the funds cleared.

What NuvoTime supports

NuvoTime connects project work with customer invoice preparation.

The workflow can include:

• Customers and contacts
• Projects and jobs
• Employee time logs
• Billable and non-billable classification
• Manager approval and adjustment
• Project default rates
• Job-specific rate overrides
• Products and services
• Hourly, fixed, quantity, service, and product lines
• Editable invoice descriptions and amounts
• Currency and sales-tax settings
• Invoice statuses
• Payment records
• Invoice PDFs
• Customer email delivery
• Sales-tax collected summaries
• Remittance-preparation summaries

The purpose is to reduce the gap between work completed and invoices prepared.

What NuvoTime does not replace in accounting software

NuvoTime helps small service businesses manage the operational path from customer work to invoice preparation. It is not intended to replace a complete accounting system.

A full accounting platform may still be needed for:

• General ledger
• Chart of accounts
• Double-entry bookkeeping
• Bank feeds and reconciliation
• Accounts payable
• Vendor bills
• Purchase accounting
• Expense management
• Inventory valuation
• Depreciation
• Formal financial statements
• Cash-flow statements
• Balance sheets
• Foreign-exchange accounting
• Credit notes and advanced adjustments
• Tax return preparation and filing
• Sales-tax remittance filing
• Year-end accounting
• Accountant access and audit workflows

The business may prepare and track customer invoices in NuvoTime, then record or synchronize the necessary financial information with its accounting software.

This distinction keeps NuvoTime focused on the work that happens before accounting: what employees completed, how long it took, what was approved, and what the customer should be billed.

Keep the billing workflow practical

A small service business does not need a complicated billing process for every project.

The essential controls are:

• Record time against the correct work.
• Review time before billing.
• Separate payable and billable hours.
• Apply the correct customer rate.
• Add non-time charges clearly.
• Review currency and tax settings.
• Keep the invoice editable while it is a draft.
• Preserve issued invoices and payment history.
• Track collected sales tax separately.
• Use accounting software for formal bookkeeping and remittance.

The goal is not to turn project managers into accountants.

The goal is to give them a reliable path from completed work to a clear customer invoice—without rebuilding the story from spreadsheets, messages, and memory.

Read the main guide: Customer and Project Management for Small Service Businesses.

Previous: How to Track Project Time Without Making Timesheets Complicated.