Proforma, quote and invoice generator

How to Create a Quote (Proforma Invoice) Your Customer Understands Immediately

A proforma invoice is not an invoice, and that is the first thing to clarify both to yourself and to the customer. It announces payment before delivery of goods or services, so the customer must be able to see three things from it without asking for additional explanations: what they are paying for, how much they are paying, and by when.

Good practice is for the proforma invoice to contain the number and date of issue, seller and buyer details, a description of items with quantity and unit price, VAT calculated by rate, the total amount, and a payment reference number. If the validity period is limited, state it explicitly, for example "this proforma invoice is valid until 15.09." This way you avoid a situation where the customer pays based on an old price.

For services, it is useful to add a brief description of the scope of work next to the item, because "consulting service, 1 pc" tells neither you nor the customer anything when a dispute arises.

What Is an Offer and How It Differs from a Proforma Invoice

An offer comes before the agreement. It proposes the price, terms, and deadline to the customer, and an obligation arises only upon acceptance of the offer. The proforma invoice comes later, when the job has already been agreed and an advance payment or the full amount needs to be collected before delivery.

In practice, this means an offer can contain options and variants (for example, a basic and an extended package), while a proforma invoice should be unambiguous. If you list multiple items with different VAT rates in an offer, the generator will display the total for each rate separately, which is useful when the customer asks for a breakdown.

Practical tip: number your offers and proforma invoices using the same logic (for example 2024-045) and keep a record of which offer turned into a proforma invoice. When the customer calls and says "that offer from last month," the number settles half the conversation.

How VAT Is Calculated in a Proforma Invoice and Offer

The base is the amount excluding VAT. The rate is applied to it, and the total amount is the sum of the base and the VAT. If you have items with different rates, VAT is calculated for each group of items separately, and the resulting amounts are then added together. That is why it is important that each item has the correct rate assigned, rather than treating the entire offer at a single rate.

Typical mistakes that recur:

1. VAT is calculated on the total amount that already includes VAT, so the tax is charged twice.
2. All items get the general rate, even though some of them are subject to a special rate.
3. Rounding is done at the end, so the sum of the items does not match the total amount.
4. For a foreign client, domestic VAT is charged even though there is no basis for it.

For foreign buyers, check whether the transaction is exempt and what is stated as the basis for the exemption. If you are not sure, consult your accountant before sending the document, because an error in the base later requires corrections and additional communication.

Most Common Mistakes When Issuing Proforma Invoices and Offers

Besides the calculation, small formatting details cause the most problems. The company registration number or VAT number (PIB) is missing, the amount is not clearly marked as "with VAT" or "without VAT," and the payment reference number differs from the one in the offer. The customer then pays the wrong amount or to the wrong account, and you spend a day reconciling records.

Also pay attention to the payment deadline: if one is stated, it must be the same in the proforma invoice and in the accompanying email. When a job spans more than one document, for example an offer with multiple phases and advance payments, manual reconciliation of numbers and amounts quickly becomes a source of errors. In such cases, EVI Solutions can help connect document issuance with your system and accounting, but for individual proforma invoices and offers a generator is enough.

Finally, download the PDF and read it as a customer would: can you tell from it what is being paid for and why. If you have to explain the document over the phone, it is probably missing a sentence or two of description.