Consulting is one of the fastest-growing professional service categories in Nigeria. Strategy consultants, HR advisers, IT consultants, financial advisers, and management consultants all face the same challenge: how do you bill clients professionally, stay FIRS-compliant, and get paid on time?
This guide covers everything Nigerian consultants need to know about invoicing - from billing structures to VAT, withholding tax, and enforcement.
Consulting Billing Models and How to Invoice Each
The right invoice format depends on how you price your consulting work.
1. Day Rate / Hourly Rate Consulting
The most common billing model for independent Nigerian consultants.
Invoice structure: | Description | Rate | Days/Hours | Amount | |---|---|---|---| | Strategy consulting - market entry assessment | ₦75,000/day | 5 days | ₦375,000 | | Subtotal | | | ₦375,000 | | VAT (7.5%) | | | ₦28,125 | | Total | | | ₦403,125 |
Always specify: the period covered, the number of days or hours worked, and your agreed rate. Do not simply write "Consulting fees - ₦375,000."
2. Project-Based (Fixed Fee)
A single fixed price for a defined deliverable - e.g., a market feasibility study, a process audit, or a business plan.
Invoice structure: | Description | Amount | |---|---| | Organisational restructuring review - report and recommendations (delivered 28 Feb 2026) | ₦1,200,000 | | Subtotal | ₦1,200,000 | | VAT (7.5%) | ₦90,000 | | Total | ₦1,290,000 |
For large fixed-fee projects, split into milestone invoices:
- 40% on project commencement
- 30% at mid-point deliverable
- 30% on final delivery
3. Monthly Retainer
A fixed monthly fee for ongoing availability and advisory services. Common for board advisers, outsourced CFOs, and IT consultants.
Invoice structure: | Description | Amount | |---|---| | Monthly retainer - financial advisory services (March 2026) | ₦350,000 | | Subtotal | ₦350,000 | | VAT (7.5%) | ₦26,250 | | Total | ₦376,250 |
Send retainer invoices on the same date each month - ideally 5 days before the month starts or on the first working day of the month.
4. Success / Contingency Fee
A percentage of the value delivered - common in fundraising, M&A advisory, and sales consulting.
Invoice structure: | Description | Amount | |---|---| | Success fee - 3% of ₦50,000,000 transaction value (per signed agreement dated 10 Jan 2026) | ₦1,500,000 | | Subtotal | ₦1,500,000 | | VAT (7.5%) | ₦112,500 | | Total | ₦1,612,500 |
Always reference the agreement or engagement letter that defines the success fee terms.
Mandatory Elements on a Nigerian Consulting Invoice
Under FIRS guidelines, every consulting invoice should include:
- Your name or business name and address
- Tax Identification Number (TIN) - if VAT-registered
- Client name and address - including their TIN for B2B invoices
- Unique invoice number - sequential (e.g., CONS-2026-014)
- Invoice date and due date
- Itemised services - not a lump sum
- VAT calculated separately at 7.5% (if registered)
- Payment details - bank account or Paystack link
VAT for Nigerian Consultants
If your annual consulting income exceeds ₦25 million, you must register for VAT with FIRS and charge 7.5% on all invoices.
If you are below the threshold, VAT registration is optional - but you cannot charge VAT without being registered. Many consultants register voluntarily to appear more credible with corporate clients.
Tip: Corporate clients who are VAT-registered can reclaim the VAT you charge as input VAT. This means your VAT is not a cost to them - registering removes a potential objection to your rates.
Withholding Tax (WHT) on Consulting Fees
Corporate clients in Nigeria are legally required to deduct Withholding Tax (WHT) from payments to consultants:
- 5% WHT on payments to companies
- 5% WHT on payments to individuals (for management and consulting services)
This is deducted from your invoice total (pre-VAT) and remitted to FIRS by your client. Your client must issue you a WHT credit note, which you use to offset your annual income tax or company tax bill.
Practical example:
Your consulting invoice: ₦500,000 + VAT (₦37,500) = ₦537,500
Client deducts WHT (5% of ₦500,000): ₦25,000
Client pays you: ₦512,500
You receive a WHT credit note for ₦25,000, reducing your tax liability at year-end.
Getting Your Consulting Invoices Paid
Use a Formal Engagement Letter
Before starting any consulting engagement, issue a signed engagement letter or contract that specifies:
- Scope of work
- Fee structure and billing schedule
- Payment terms (due date, late fees)
- Cancellation terms
This document is your legal basis for enforcing payment.
Collect a Deposit
For new clients, require 30–50% upfront before work commences. Never start a consulting engagement without a signed agreement and deposit in your account.
Set Clear Due Dates
"Net 30" is standard in corporate Nigeria, but freelance consultants should aim for "Net 14" or "Net 7". Always state the specific due date on the invoice - not just "30 days."
Add Late Payment Terms
State on every invoice: "Overdue balances attract interest at 3% per month from the due date." This is legally enforceable and encourages timely payment.
Make Payment Easy
Include a Paystack payment link on your invoice so clients can pay instantly by card or bank transfer - no need to visit a bank or initiate a USSD transfer.
Create Professional Consulting Invoices
InvoiceGenerator.ng is built for Nigerian professionals. Create itemised consulting invoices with automatic VAT calculation, payment terms, and Paystack integration - shareable via WhatsApp or email in seconds.
See also our full Nigerian Invoicing Guide covering FIRS compliance, VAT registration, and best billing practices for service professionals.