Introduction

Every freelancer and every company has to deal with the topic "number ranges" at the beginning. Therefore, we dedicate ourselves to this topic in this article, in order to give general requirements on the one hand, but also practical tips.

What do I need number ranges for?

Number ranges are used for various business objects such as customers, offers, orders and invoices to ensure unique identification both for the company itself and for other companies and authorities. This way, misunderstandings are reduced in communication with customers, authorities and other business partners, and more transparency and traceability are created.

However, there are also legal provisions, e.g. how a numbering for invoices has to be designed. Section 14 of the German Value Added Tax Act (Umsatzsteuergesetz) states with regard to the numbering of invoices that an invoice must show "a consecutive number with one or more series of numbers which is assigned once by the issuer of the invoice for the purpose of identifying the invoice".

What do I need to consider when designing number ranges?

If we break down the above legal requirements into their individual components, we can see the following requirements:

  • consecutive number: This means that each new invoice must be numbered higher than the previous invoice.
  • With one or more series of numbers: This means that a combination of several consecutive numbers, which include e.g. the year or the month, is also possible.

Beyond that, there are aspects that revolve around the information content of a numbering:

  • Time information: By including a year and, if necessary, also a month number, it can be directly recognized, e.g. for invoices, in which rough period this was created.
  • Type: By specifying abbreviations that designate the type of business object, e.g. CU = customer, IN = invoice, OF = offer, etc., it is ensured that, for example, in communication with a customer, a named number can be correctly classified immediately.
  • Cosmetics: However, "cosmetic" adjustments are also conceivable. For example, sequential numbers are often zeroed to n digits in order to always have identifiers of the same length, e.g. CU-2021-00001.

What is a recommended course of action?

In order to meet the legal requirements and to increase the information content of the numbering, the following procedure is useful:

  • Prefixes assigned for each type of business object: CU = Customer, OF = Offer, OR = Order, IO = Internal Order, IN = Invoice.
  • Year/Month Number: All numbering should include a year number (can be 2 or 4 digits) and a month number if needed.
  • Consecutive numbering: The consecutive number should be placed at the end. This can be reset to 1 every year or month depending on the year or year/month number.
  • Nulling: The sequential number should be zeroed to a certain number. Here the expected quantity of customers, offers, ... should be taken into account. However, it is advisable to use a number of zeros uniformly for all number ranges in order to have only one rule for checking a valid number.
  • Separators: Separators should be used between the different components for better readability.

This results in the following numbering pattern:

  • -- e.g. CU-2021-10001 or
  • --- e.g. CU-2021-01-10001

How does it work in foreknown?

foreknown allows a flexible design of the number ranges for customers, offers, orders, internal orders and invoices. For this purpose, variables are offered for the current year, the current month, the current day and the consecutive number. A start value can be stored and a reset of the counter on a daily, monthly or yearly basis is possible.

Documentation-Link: You can find all details in the online documentation under "Features / System Administration / Number Ranges".