Supplier invoices · Guide

What is a supplier invoice? What it must show in Ireland

A supplier invoice is the bill a supplier sends you for goods or services. If you are VAT registered, it is also your evidence for reclaiming VAT, so the details on it matter.

Updated 26 October 2026 · Nexus Digital Ireland

What a supplier invoice is

A supplier invoice (also called a purchase invoice or a bill) is the document a supplier sends you asking to be paid for goods or services they have provided. To the supplier it is a sales invoice; to you it is a supplier invoice, and it belongs in your accounts payable until it is paid.

It is different from a quote (a price offered before you agree), a purchase order (what you asked for) and a receipt (proof you have paid). A pro forma invoice is a request for payment in advance, not a VAT invoice, so you cannot reclaim VAT on it; wait for the proper invoice.

Why the details on it matter

VAT: if your business is VAT registered, you generally need a valid VAT invoice to reclaim the VAT you were charged.
Paying the right amount: the invoice is what you check against the quote or order before money leaves the account.
Records: Revenue, your accountant, customers and auditors (including ISO audits) may ask to see what you bought, from whom and why.

What an Irish VAT invoice must show

Revenue sets out the details a VAT invoice must contain. When a VAT-registered supplier invoices your business, check that it shows:

Date of issue: The date the invoice was issued.
A unique invoice number: From a sequential series, so each invoice can be identified.
The supplier's details: Full name, address and VAT registration number.
Your details: Your business's full name and address. Where the reverse charge applies, your VAT number too.
What was supplied: The quantity and type of goods, or the extent and type of services.
Date of supply: When the goods or services were supplied, where this is different from the invoice date.
Prices before VAT: The unit price excluding VAT, and any discounts not already in the unit price.
The total before VAT: The amount charged, excluding VAT.
VAT rate and amount: The VAT rate applied, and the VAT amount at each rate.
Special wording where it applies: For example a reference to the reverse charge, an exemption or a margin scheme.

This is a general summary of Revenue's published rules, not tax advice. Some schemes and cross-border supplies have extra requirements; check revenue.ie or ask your accountant about your situation.

Special cases worth knowing

Suppliers that are not VAT registered do not charge VAT and do not issue VAT invoices. Their invoice is still your record of the purchase.
Reverse charge: for many services bought from suppliers in other EU countries, and some domestic supplies such as certain construction services, the supplier does not charge VAT and you account for it instead. The invoice should say so.
Credit notes: if a supplier reduces what you owe, they issue a credit note that refers back to the original invoice. Keep both together.
Electronic invoices: PDF and other electronic invoices are fine, as long as they are kept so that they stay readable and unaltered.

When invoices are issued and how long to keep them

Revenue expects a VAT-registered supplier to issue a VAT invoice within 15 days of the end of the month in which the goods or services were supplied. If an invoice for a supply is missing, ask for it promptly rather than waiting for the next statement.

Keep supplier invoices, credit notes and related records for at least six years. Keeping them in one place, linked to the supplier and the purchase, makes VAT returns, year-end and audits far quicker.

Mistakes to check for before you pay

The same invoice arriving twice (by email and post, or resent as a reminder) and being paid twice.
A price higher than the quote, order or last invoice, especially a unit price that has crept up.
The VAT number, VAT rate or VAT maths missing or wrong.
The invoice made out to the wrong name, such as a director personally instead of the company.
Goods or services charged that were never received, or charged before they were supplied.
No record of who agreed the purchase, so nobody can say whether it should be paid.

How the Operations Register handles supplier invoices

The Nexus Business Operations Register keeps every supplier invoice with its supplier, its approval and its evidence, so the checks above happen as part of your normal routine.

Upload an invoice and confirm the details Nexus prepares, instead of typing them. A person confirms every invoice.
An invoice that has already been uploaded is flagged before it can be paid twice.
Unit price changes against earlier invoices are flagged, kept separate from a bigger order.
Invoices sit with the purchase approval, the supplier record and any job they belong to, ready for VAT returns, year-end or an audit.

Invoice upload Price change alerts Accounts payable

Questions

What is an invoice?

An invoice is a document a business sends to ask to be paid for goods or services it has supplied. It shows who is selling and buying, what was supplied, the price, any VAT and when payment is due. The seller calls it a sales invoice; the buyer calls it a supplier or purchase invoice.

What is an invoice number?

A unique reference the supplier gives each invoice, taken from a sequential series, so every invoice can be identified and none is missed or repeated. On an Irish VAT invoice it is required. Checking invoice numbers is also the simplest way to catch an invoice that has arrived twice.

Is a supplier invoice the same as a bill?

Yes. Supplier invoice, purchase invoice and bill all mean the invoice a supplier sends you for payment. Your supplier calls the same document a sales invoice.

Can I reclaim VAT without a VAT invoice?

Generally no. A VAT-registered business needs a valid VAT invoice showing the required details to reclaim the VAT it was charged. A pro forma invoice or a statement is not enough.

Are PDF or scanned invoices acceptable?

Yes. Electronic invoices are acceptable, provided they are stored so that they remain readable and are not altered.

How long should I keep supplier invoices?

Keep them, with related records, for at least six years.

What should I do if an invoice is missing details?

Ask the supplier for a corrected invoice before you pay or claim the VAT. Keep the corrected version with the original request.

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