Construction Progress Billing Under ZATCA E-Invoicing: How to Handle Advance Payments and Retention



Processing construction progress billing under Phase 2 of e-invoicing is one of the most complex accounting and technical challenges facing engineering and construction companies in the Kingdom of Saudi Arabia. Regulations issued by the Zakat, Tax and Customs Authority (ZATCA) require transforming all printed progress sheets and paper certificates into encrypted XML (UBL 2.1) electronic tax invoices.

This includes processing advance payment recoveries and retention money deductions with extreme precision to avoid double taxation or breaking the invoice's cryptographic chain. This detailed guide offers a comprehensive roadmap for financial managers and accountants to manage these transactions in full compliance.

📌 Key Takeaways

• Legal Value of Progress Billing: The technical distinction between a progress claim, a work completion certificate, and an approved tax invoice.
• Managing Advance Payments: How to settle and recover advance payments within invoice lines without doubling the tax base.
• Retention Money: The correct tax treatment for deduction percentages and issuing invoices upon final release.
• Technical Processing Matrix: A reference table linking construction events to tax treatments and XML encoding fields.
• Wafeq’s Smart Solutions: How the system automates progress billing lines and tax settlements according to Fatoora platform requirements.
• Frequently Asked Questions: Direct answers to the most prominent operational queries in construction accounting.

Is a Construction Progress Bill Considered an Accepted Tax Invoice by ZATCA?

Traditional practice in the construction sector involves preparing periodic progress bills that reflect completion percentages and works executed by the main contractor or subcontractor, which are then submitted to the consultant or owner for approval. However, from a regulatory standpoint, a paper progress bill or bill of quantities is not considered an accepted tax invoice by ZATCA unless it is issued electronically as an approved tax invoice through an accounting system integrated with the authority.

Legal Date of Supply for VAT in Long-Term Construction Contracts

Construction contracts are classified as continuous supplies. According to the VAT Executive Regulations issued by the tax authority, the tax due date is determined by whichever of the following events occurs first:

• The date the tax invoice is issued for the progress bill or part of it.
• The date of receiving the cash payment (in full or in part).
• The date of completing the supply of services or works (generally represented by the approval date of the work completion certificate).
• The lapse of 12 months from the date the service was rendered without an invoice being issued or payment being made.

Difference Between a Work Completion Certificate (WCC) and a Progress Claim

The finance department must clearly distinguish between three core documents in the audit trail:

• Progress Claim / Draft Bill: An internal document submitted to the consultant to review quantities; it carries no tax obligations.
• Work Completion Certificate (WCC / Valuation Certificate): The document in which the consultant formally accepts the executed works and their financial value. This document serves as proof of the date of supply.
• Electronic Tax Invoice: The certified legal document issued by a licensed accounting system programmatically connected to ZATCA’s portal. It is the only document registered in the tax returns of both parties and allows the owner to deduct input VAT.

Processing Advance Payments and Tax Settlements in XML Invoices

Advance payments at the start of construction projects are among the most sensitive points, given the necessity to collect tax upon receipt and then gradually settle it with each current progress bill.

1. Issuing a Tax Invoice for the Advance Payment Upon Receipt

When signing the contract and receiving an advance payment (e.g., 10% of the project value), the contractor must immediately issue an electronic tax invoice for this nominal amount.

• Tax Base: The received amount is considered inclusive of VAT (if agreed upon) or calculated as a net amount with 15% added.
• Technical Processing: The invoice is recorded in the accounting system, linked to the project file, and submitted to ZATCA to obtain the cryptographic stamp and generate the QR code.

2. Settling Advance Payment Deductions Within Progress Bill Lines Without Double Taxation

When issuing a current progress bill for executed works, the bill’s value includes a portion previously paid via the advance payment. To avoid double taxation, an advance payment recovery line item must be inserted as an independent line with the same tax treatment within the same invoice.

In the progress bill’s XML file, the deduction line is recorded with an explicit reference to the tactical code for tax-accepted discounts, ensuring net tax is calculated accurately without rejection from ZATCA’s automated audit algorithms.

Learn more about: Construction invoice template: The "Why" Behind the Specialized Invoice

Processing Retention Money and Performance Guarantees

Most construction contracts mandate deducting a percentage (usually ranging between 5% and 10%) from each progress bill as retention money for performance guarantees, to be paid to the contractor after final project handover or the end of the maintenance period.

A. Is Tax Calculated on the Gross Progress Bill or the Net After Retention?

Instructions issued by ZATCA specify that withholding retention funds does not alter the total value of the service rendered. Accordingly:

• VAT is due on the total value of executed works in the progress bill before deducting retention money.
• Retention money is not considered a trade discount or price reduction on the service; it is merely a contractual arrangement to defer the delivery of a portion of cash liquidity. Therefore, the contractor is required to pay full tax on completed work on the invoice date.

Tax Treatment Upon Releasing Retention Money at Project End

When the maintenance period ends, and retention funds are released and paid to the contractor:

• No new tax invoice with VAT is issued, because tax was already paid in full within the electronic invoices for previous periodic progress bills.
• Only a collection document or non-tax receipt voucher is issued to record cash flow and clear accounts payable/receivable in the accounting system.

Accounting and Technical Processing Matrix for Progress Bills

To clarify the distinction between accounting events, tax applications, and technical encoding in XML files under e-invoicing standards, the following table summarizes the complete cycle:

How Wafeq Automatically Solves Construction Progress Billing Complexities

Attempting to match these complex accounting treatments with ZATCA’s strict encryption requirements poses a massive operational burden on IT and finance teams in construction companies. This is where specialized accounting for construction businesses becomes critical—and where Wafeq's accounting system stands out as a specialized, certified solution providing full workflow automation for progress billing.



Key Cloud Features for the Construction Sector in Wafeq

• Multi-Line Progress Engine Allows creating progress invoices containing completion items, advance recovery lines, and retention deductions in just a few clicks.
• Automated Tax Settlement Wafeq automatically routes each line in the progress bill to its correct slot in the XML structure, ensuring tax is calculated on net completed works after advance recovery and before retention withholding.
• Instant Authentication with ZATCA Connects directly with the Fatoora portal, generating the Cryptographic Stamp, QR Code, and Hash Chaining for every progress bill without manual intervention.
• Credit and Debit Note Management When consultant adjustments occur on progress values, the system allows issuing fully compliant credit notes. Read our comprehensive guide on: how to handle credit notes according to ZATCA rules for more practical details.
• Flexibility for Growing Firms and Contractors If you are looking for a comprehensive evaluation of certified solutions available in the Saudi market, check out the best e-invoicing software solutions in Saudi Arabia for a full comparison.

Read Also: How Accounting Software Empowers Business Owners to Master Their Finances

Managing construction progress billing under e-invoicing mandates is no longer just about entering numbers into spreadsheets; it is an accounting engineering process requiring a system that merges specialized understanding of construction contracts with absolute programmatic compliance with ZATCA standards. Failing to process advance payments or retention funds correctly may expose your firm to delay fines, tax reassessments, or rejected progress claims by major project owners and government entities.

FAQs about Construction Progress Billing Under ZATCA E-Invoicing

When must a tax invoice be issued for a construction progress bill?

An electronic tax invoice must be issued immediately upon approval of the progress bill and issuance of the Work Completion Certificate by the consultant, or upon receiving any payment against the progress bill, whichever comes first—provided it does not exceed 15 days from the end of the month in which the supply occurred.

Is VAT calculated on retention money immediately?

Yes, tax is calculated on the total value of executed works in the progress bill before deducting retention money, because retention withholding is a deferral of cash settlement, not a reduction in the price of the rendered service.

How is an advance payment deducted in an e-invoice without XML errors?

An advance payment is deducted by adding a dedicated discount line (Allowance/Discount Line) equal to the advance recovery amount due for that progress bill, linked to the same tax category (15%), accurately reducing the total taxable base before encryption.

What is the correct action if a progress bill is rejected or value-adjusted by the consultant?

If an electronic tax invoice was issued for the progress bill and the consultant subsequently adjusted the value downwards, the contractor must issue an electronic Credit Note referencing the Universally Unique Identifier (UUID) of the original invoice to adjust the tax liability with ZATCA.

Does a printed progress sheet replace issuing an e-invoice from an approved system?

No, paper progress sheets and printed bills of quantities are considered operational proof documents only. ZATCA does not recognize them as tax-related substitutes for a fully compliant electronic tax invoice issued from a certified technical solution.