How to Write a GTM Stack Inventory in a Spreadsheet

Do you actually know what is in your GTM stack?

Most teams do not, at least not fully. Tools get added by different people for different campaigns, connections pile up, and nobody keeps a single list. A GTM stack inventory in a spreadsheet fixes that. It records every tool, who owns it, what data it touches, what it costs, and what depends on it.

This tutorial is written for one reader: a RevOps lead, marketing ops manager, or founder who just inherited a go-to-market stack and needs to understand it before changing anything. If you built every tool yourself and remember every connection, you may not need this. Most people in that seat do.

I like to start a GTM engineering engagement with some version of this inventory, because I cannot safely change a system I have not mapped. The spreadsheet below takes a few hours to build and saves days of confusion later.

What is a GTM stack inventory and why build one?

It is a single spreadsheet listing every tool involved in finding, converting, and keeping customers, with its owner, purpose, cost, data flows, and dependencies. You build it to answer basic questions fast: what does the company pay for, what breaks if this tool goes away, and where does each piece of customer data live.

Those questions come up constantly. Finance asks why software costs rose. A tool announces a price change. An automation breaks and nobody knows which system feeds it. An employee leaves and takes the only knowledge of a critical integration with them. The inventory turns each of these from a scramble into a lookup.

It also exposes waste and risk. Duplicate tools doing the same job, seats nobody uses, and critical workflows that depend on one person's personal account all show up once everything is in one place.

Step one: how do you set up the spreadsheet?

Create a Google Sheet or Excel workbook with three tabs: Tools, Data Flows, and Changes. The Tools tab has one row per tool. The Data Flows tab has one row per connection between tools. The Changes tab logs every addition, removal, or major configuration change with a date.

On the Tools tab, use these columns: tool name, category, purpose in one sentence, business owner, technical owner, plan or tier, monthly or annual cost, renewal date, number of seats, login method, and notes. Keep the purpose column short and specific, such as "enriches new inbound leads with company data".

On the Data Flows tab, use: source tool, destination tool, what data moves, how it moves (native integration, Zapier, Make, n8n, custom script), trigger or schedule, owner, and what breaks if it stops. This tab is where most of the value lives, because data flows are the part people forget.

Step two: where do you find every tool?

Check four places: finance records, single sign-on or identity provider logs, browser bookmarks and password managers of key team members, and the integration settings inside your main systems. Finance shows what you pay for. Integration settings show what connects. Together they catch most tools.

Start with finance. Pull the last twelve months of software charges from the company card and accounting system. Every recurring charge is a candidate tool. Then check the CRM, marketing automation platform, and website for connected apps, since many tools appear there even if billed through someone's personal card.

Finally, interview the team. Ask each person which tools they log into weekly and which automations they rely on. People often use free tiers or trials that never appear in finance records. Those hidden tools sometimes hold important customer data.

Step three: how do you map the data flows?

Work outward from your system of record, usually the CRM. For each connected tool, record what data enters the CRM from it and what leaves the CRM to it. Then do the same for the website forms, the enrichment tools, and the outbound tools. Draw it on paper first if it helps.

Open each automation platform and list every active workflow. For Zapier, Make, or n8n, record the trigger app, the action apps, and what the workflow does in one sentence. Mark any workflow that runs under a personal account or a former employee's login. Those are your highest risk items.

For each flow, ask what breaks if it stops. "New demo requests stop reaching sales" is critical. "A weekly report stops updating" is minor. That column lets you prioritize monitoring and documentation, which I cover in more depth in versioning Zapier and Make workflows.

Step four: how do you record ownership and cost?

Assign two owners per tool: a business owner who decides whether it is worth paying for, and a technical owner who can configure and fix it. Record cost, plan, seats, and renewal date from invoices or account settings. Leave a cell blank and highlight it when you do not know, rather than guessing.

Seats deserve attention. Compare the number of paid seats to the number of people who actually logged in recently, where the tool shows that. Unused seats are the easiest savings in most stacks. Usage-based tools need a different view, so note how they bill and who watches spend.

Some GTM tools bill by usage or credits, which makes spend monitoring part of the inventory's job. If your CRM or enrichment tools bill by credits, record the limits and alerts you have set. I walked through one example in setting HubSpot credit spend limits.

Step five: how do you flag risk and overlap?

Add three columns to the Tools tab: overlap, risk, and action. Overlap notes any other tool doing a similar job. Risk notes single points of failure such as personal logins, undocumented workflows, or tools holding sensitive data without an owner. Action records what you plan to do next.

Common overlaps include two enrichment providers, two scheduling tools, or a marketing automation platform and a separate email tool both sending to the same contacts. Overlap is not always bad, but it should be deliberate. Note why both exist, or plan to consolidate.

Data risk matters too. Note which tools store personal data and whether contact suppression is respected across them. If someone unsubscribes in one tool, does every other tool know? My guide on building a do not contact list that every tool respects covers that problem directly.

Step six: how do you keep the inventory alive?

Make updating it part of the process for adding or removing any tool. Nobody buys or cancels GTM software without adding a row to the Changes tab. Review the full inventory quarterly with the business and technical owners. Check renewal dates monthly so nothing auto-renews by surprise.

A small automation helps. A monthly reminder to the RevOps owner listing tools with renewals in the next sixty days keeps decisions ahead of the billing date. You can build that from the renewal date column with a simple scheduled workflow.

Share the inventory widely but control editing. Everyone in revenue roles should be able to see what tools exist and who owns them. Only owners should edit. Visibility alone prevents a lot of duplicate purchases, because people check the list before buying something new.

What should you do next?

Block three hours this week. Create the spreadsheet with the three tabs, pull twelve months of software charges, and list every tool. Then open your CRM and automation platforms and map the data flows. Mark unknown owners and personal logins in a bright color.

Share the draft with the team and ask them to fill gaps. Then pick the three highest risk items, such as critical workflows on personal accounts, and fix those first. Set a quarterly review on the calendar before you close the spreadsheet.

If you want help mapping your GTM stack, cleaning up risky workflows, or deciding what to consolidate, reach out through pravinkumar.co. I build the websites and the automations behind them for lead generation, and a clear stack inventory is where that work usually begins.