Financial Modelling Standards

The different modelling standards are more alike than they are different. They all emphasise similar elements of good practice. What's important is to pick one and apply it consistently.

The system that I'm going to teach you in this book is based on the FAST Standard. It's one of a number of modelling standards that exist.

In my view, the different standards are more alike than they are different. They all emphasise similar elements of good practice. What's important is to pick one and apply it consistently.

In this chapter I'm going to give an overview of what's already out there so that you can learn from what other people have discovered about standardising models and developing a repeatable system.

In the previous chapters, I mentioned that there are two parts to an effective modelling system; the structure of the model, and the workflows that you use within it.

The modelling standards tend to talk more to the structure of the model and address the question - "what makes a well structured model?"

How common is the use of modelling standards?

According to the 2021 Financial Modelling Survey, 95% of modellers believe that standards are important. 41% of modellers work in organisations where standards are applied rigorously. In professional services firms, this figure goes up to 64%.

Of those who use a standard, the majority use an in-house code of best practice:

Source: 2021 Financial Modelling Survey. The survey notes that there is selection bias in the survey data that may overstate the usage of FAST.

So while modellers believe that standards are important, and many are following a standard, outside professional services, most are not.

An overview of standards

There are links to help you find out more about each of these in the notes for this chapter.

ICAEW modelling code

The ICAEW Financial Modelling Code is a great place to start. It gives a series of recommendations for good spreadsheet practice. It's been compiled by a broad group of practitioners and so has wide applicability to different user requirements.


The approach that I use and teach is based on FAST. FAST is highly prescriptive and certainly not everybody's cup of tea. Some people dislike (quite strongly!) the use of links or "call ups" throughout the model and the fact that this increases the number of rows it takes to complete a calculation.

FAST stands for Flexible, Appropriate, Structured and Transparent.

FAST is "open-source" and maintained by a not-for-profit company called the FAST Standards Organisation. Unfortunately, not much development has gone into FAST over recent years which is somewhat of a missed opportunity.

Smart / Mazars financial modelling standard.

SMART became the Mazars financial modelling standard after Mazars acquired Corality (who originated SMART).

They have a list of guiding philosophies that most professional modellers would agree with:

PwCs Global Financial Modelling Guide

A recent addition to this field is PwCs Global Financial Modelling Guidelines document published in January 2020. It's a well put together document with enough detail to be applicable in practical terms, and broad enough to apply to most time series modelling situations.

The document is made up of 5 core principles and 10 practical model design guidelines. The "Essence of spreadsheet evil section" is also well worth reading.

The five guiding principles include some useful thinking, clearly borne out of decades of collective modelling wisdom. These are:

See the resources section below for the download link.

Operis / "named range" approach

Operis and a number of other companies apply an approach that, on the surface, appears quite different but which has the same level of discipline and structure as the others, and adheres to a lot of the same principles.

Their system makes extensive use of "named ranges" in the model build. It's a highly systematic and well thought through process for modelling. Where FAST uses calculation blocks to ensure that the precedents to formulas are visible and easily read alongside the formula, by naming everything, the "Operis" approach means that formulas can be "read" like sentences.

Like the extensive use of call-ups in FAST, extensive use of named ranges is not to everybody's taste.


BPM was the first to systematically codify a modelling standard back in 2003. BPM is now under the Modano brand. There is an interesting tool on the Modano website which allows you to customise your own spreadsheet best practice guidelines.

I recommend that you find what each of these has to offer and how it might develop your own thinking. Compare to what I'm teaching in this book and find an approach that works for you.


Sign in or become a Financial Modelling Handbook member to join the conversation.
Just enter your email below to get a log in link.

Subscribe to Financial Modelling Handbook

Don’t miss out on the latest financial modelling guides. Sign up now to get access to the library of members-only guides.