FreelancersTax

Net, gross and the tax rate: the formula freelancers get wrong on their first invoice

SENULA COMPANY · 2026-09-19 · 5 min read

The first invoice a freelancer sends often has a tax calculation error. The mistake is small enough to go unnoticed on one invoice, but it compounds over months and creates discrepancies when tax filing season arrives.

The core issue is a single wrong formula: subtracting the tax percentage from the gross total instead of dividing by it.

From net to gross

The net amount is your fee before tax. The gross amount is what the client pays. The formula connecting them is straightforward.

Net × (1 + Tax Rate) = Gross

If your net fee is 1,000 and the tax rate is 10%, multiply 1,000 by 1.10. The gross total is 1,100, of which 100 is tax. At a 20% rate, multiply by 1.20 to get 1,200, of which 200 is tax.

Enter your net fee and tax rate in VAT / Sales Tax Calculator to confirm the gross total before adding it to your invoice.

The reverse formula most people get wrong

When you receive a gross payment and need to find the original net amount, the instinct is to subtract the tax percentage. This does not work.

Take a gross amount of 1,100 that includes 10% tax. Subtracting 10% gives 1,100 − 110 = 990. But the original net was 1,000, not 990.

The error happens because tax is calculated as a percentage of the net, not the gross. Ten percent of 1,000 (the net) is 100. Ten percent of 1,100 (the gross) is 110. These are different numbers.

The correct reverse formula is:

Gross ÷ (1 + Tax Rate) = Net

Dividing 1,100 by 1.10 gives exactly 1,000.

How big is the error?

The gap between the wrong method and the right one grows with both the amount and the tax rate.

At a 20% rate on a 1,000-unit fee, the error is 40 per invoice. A freelancer issuing two invoices a month accumulates 960 in misreported figures over a year.

Worked example 1: a graphic designer's logo project

A graphic designer charges a net fee of 850 for a logo. The applicable tax rate is 7.5%.

Tax: 850 × 0.075 = 63.75. Gross total: 850 + 63.75 = 913.75. The client pays 913.75.

At tax filing time, the designer needs to confirm net revenue. Using the wrong method: 913.75 × 0.075 = 68.53, so net = 913.75 − 68.53 = 845.22. That is 4.78 less than the actual net of 850. The designer would under-report revenue and under-remit tax.

Using the correct formula: 913.75 ÷ 1.075 = 850.00. Tax = 63.75. Everything matches.

Worked example 2: a translator's VAT-inclusive payment

A translator receives a gross payment of 2,640 that already includes 20% VAT. The translator needs to determine net income and the VAT owed.

Wrong method: 2,640 × 0.20 = 528. Net = 2,640 − 528 = 2,112. VAT reported = 528.

Correct method: 2,640 ÷ 1.20 = 2,200. VAT = 2,640 − 2,200 = 440.

The wrong method overstates the VAT by 88 (528 − 440) and understates net income by the same amount. Over 12 monthly payments of the same size, the cumulative VAT error reaches 1,056. You can verify either direction — net to gross or gross to net — at any custom rate using VAT / Sales Tax Calculator.

Quoting prices: inclusive or exclusive?

A common source of confusion arises at the quoting stage. A freelancer quotes "1,000" for a project without specifying whether tax is included. Two outcomes follow.

If the client assumes 1,000 is the gross (tax-inclusive) price, the freelancer must extract the tax from that amount. At a 10% rate: 1,000 ÷ 1.10 = 909.09 net, with 90.91 going to tax. The freelancer takes home 909.09 instead of the intended 1,000.

If the freelancer meant 1,000 as the net price, the client owes 1,100 — a surprise addition the client did not budget for.

State whether your quoted fee includes or excludes tax in every proposal. One sentence prevents months of margin erosion.

Invoice formatting

A clear invoice lists each component so the client's accounting team can process it without guessing.

Standard structure: line items with descriptions and net amounts, a subtotal of net amounts, the tax rate and calculated tax on a separate line, and the gross total.

Sample wording: "Translation services (12,000 words): 2,200. VAT at 20%: 440. Total due: 2,640."

Avoid combining tax into the line item price without a separate tax line. Many accounting systems require the tax amount as a distinct field for reporting.

Rounding conventions

Tax calculations on individual line items often produce fractions. A net amount of 33.33 at a 10% rate yields a tax of 3.333. How you handle the fraction depends on your jurisdiction.

The most common approaches: standard rounding (round half up), where 3.335 becomes 3.34 and 3.334 becomes 3.33. Some systems require rounding up regardless of the fraction. Others truncate, cutting off the decimals entirely.

On a single invoice the difference is a fraction of a cent. Across hundreds of line items per quarter, inconsistent rounding creates mismatches between your records and the tax authority's expectations. Pick the method your jurisdiction requires, apply it consistently, and double-check totals with VAT / Sales Tax Calculator before sending the final invoice.

FAQ

Can I use one tax rate for all clients?

Only if all your clients and services fall under the same tax jurisdiction and category. Tax rates vary by country, by state or province, and sometimes by the type of service. Check the rate that applies to each specific transaction.

What if I forgot to charge tax on past invoices?

Issue a corrected invoice or a separate tax-only invoice to the client for the missing amount. Consult your local tax authority's guidelines on retroactive corrections, as penalties and interest rules differ by jurisdiction.

Does the rounding method really matter?

For a single invoice, the difference is usually under one currency unit. Over a full year of invoicing, mismatched rounding can cause your reported totals to diverge from the tax authority's calculations, which may trigger a review. Use one method consistently.