In Philippine commercial transactions, it is common for parties to negotiate a "net-of-tax" arrangement. In such cases, the payor agrees to shoulder the burden of the Expanded Withholding Tax (EWT), ensuring the payee receives a specific, fixed amount. However, for tax compliance and proper documentation (BIR Form 2307), the Bureau of Internal Revenue (BIR) requires that the tax be computed based on the Gross Amount, not the net cash received.

When a payment is stipulated as "net," the transaction must be "grossed up" to reflect the true taxable income and the corresponding withholding tax.

The Legal Framework

Under the National Internal Revenue Code (NIRC), as amended by the TRAIN Law and the EASE Law, withholding tax is an obligation of the payor (the withholding agent). The EWT is a system where the payor deducts a certain percentage from the income payment and remits it directly to the BIR. This tax is creditable against the income tax liability of the payee.

When a contract specifies a net payment, the law views the tax paid by the payor on behalf of the payee as additional income to the payee. Therefore, the "Gross Amount" is the sum of the Net Payment and the Withholding Tax.

The Mathematical Formula

To derive the Gross Amount from a Net Payment, you must account for the specific EWT rate applicable to the transaction (e.g., 1% for goods, 2% for services, 5% or 10% for rentals/professionals).

The basic algebraic relationship is: $$Gross\ Amount - (Gross\ Amount \times EWT\ Rate) = Net\ Payment$$

To find the Gross Amount, the formula is:

$$Gross\ Amount = \frac{Net\ Payment}{1 - EWT\ Rate}$$

Example Calculation:

If a service provider is to receive a net payment of ₱98,000 and the applicable EWT rate for professional services is 2%:

Identify the Rate: $2%$ or $0.02$
Calculate the Divisor: $1 - 0.02 = 0.98$
Apply Formula: $98,000 / 0.98 = 100,000$

The Gross Amount is ₱100,000, and the EWT to be remitted is ₱2,000.

The Impact of Value-Added Tax (VAT)

In the Philippines, most commercial transactions also involve a 12% VAT. It is a common error to gross up the EWT while ignoring the VAT component. If the "Net Payment" agreed upon is intended to be the final cash out-of-pocket for the payor (inclusive of VAT and EWT), the formula becomes more complex.

However, in standard accounting, VAT is usually treated separately. If the goal is to find the VAT-Inclusive Gross Amount from a Net Payment:

Gross up for EWT first to find the "Gross Amount (Net of VAT)."
Multiply by 1.12 to find the "Total Amount Payable (VAT-Inclusive)."

Component	Calculation
Net Cash to Payee	The agreed-upon amount
Gross Amount (Tax Base)	$Net\ Payment / (1 - EWT%)$
EWT Amount	$Gross\ Amount \times EWT%$
VAT (12%)	$Gross\ Amount \times 0.12$
Total Invoice Amount	$Gross\ Amount + VAT$

Key Legal Considerations

Tax Indemnity Clauses: While the BIR generally holds the withholding agent (payor) liable for the non-remittance of taxes, private contracts can shift the economic burden. However, these "net of tax" clauses do not absolve the payor from the legal duty to file returns and issue BIR Form 2307.
The "Grossed-Up" Income as Taxable: For the payee, the "Gross Amount" (which includes the tax paid on their behalf) must be declared as their gross income for Income Tax Return (ITR) purposes. Failing to do so results in under-declaration of income.
Documentation: The Official Receipt (OR) or Sales Invoice (SI) issued by the payee must reflect the Gross Amount. If the payee issues a receipt only for the net amount received, the payor will face difficulties in claiming the expense as a tax-deductible item.
Deductibility: To be deductible for income tax purposes, it is a requirement under Philippine law that the proper tax must have been withheld and remitted. If the payor "shoulders" the tax but fails to gross it up correctly, the BIR may disallow the entire expense during an audit.

Summary Table of Common EWT Rates for Gross-Up

Transaction Type	EWT Rate	Divisor for Gross-Up
Purchase of Goods (Top 20k Corps)	1%	0.99
Purchase of Services (Top 20k Corps)	2%	0.98
Rentals (Real or Personal Property)	5%	0.95
Professional Fees (Individual < ₱3M)	5%	0.95
Professional Fees (Individual > ₱3M or Corp)	10%	0.90