You have decided the spreadsheet has to go. Good. The hard part isn't choosing the tool — it's the commission software migration itself: moving years of plan logic, historical payouts and half-remembered exceptions into a new system without anyone's pay going wrong in the process. Get the migration wrong and you don't just lose time; you lose the rep trust that justified the purchase in the first place.
This is a UK-focused playbook for doing it safely. It assumes you've already picked a tool (if not, start with our buyer's guide to choosing commission software) and now have to actually switch.
TL;DR
A commission software migration goes wrong when teams treat it as a data-import job rather than a pay-critical change. The safe sequence is: clean your inputs first (CRM and plan documents), rebuild the live plan in the new tool, then run at least one full period in parallel with the old spreadsheet and reconcile the two to the penny before you cut over. Never big-bang a migration in the middle of a quarter, never migrate without a documented rollback, and communicate the change to reps before — not after — their statement looks different. The migration is finished when reps trust the new number enough to delete their own shadow spreadsheet.
A commission migration isn't a data project. It's a pay change — and people remember the month their pay went wrong.
How does a commission software migration work?
A commission software migration has five stages, and the discipline is in not skipping the boring ones. Most failed migrations skipped straight from "buy" to "cut over".
- Clean the inputs. Tidy CRM deal data and write down the live plan in plain English, including every exception. Garbage in, garbage out — the tool will faithfully reproduce a mess.
- Rebuild the plan. Configure the current plan in the new software — tiers, accelerators, splits, clawbacks and draws — without changing the plan at the same time.
- Backfill history. Load enough historical payouts that opening balances, year-to-date attainment and any in-flight clawbacks are correct from day one.
- Parallel run. Calculate at least one full period in both the old spreadsheet and the new tool, then reconcile line by line.
- Cut over. Once the two agree, switch the new tool to the source of truth, archive the spreadsheet read-only, and tell reps what's changing.
Why you should clean the data before you migrate, not after
The single biggest predictor of a smooth migration isn't the software — it's how clean your CRM and plan documentation are going in. A new commission tool calculates from your deal data; if close dates, amounts, owners and product splits are wrong in the CRM, the tool will produce wrong commission faster and more confidently than your spreadsheet did.
Spend a week before migration on three things: deduplicate and correct the deals that will drive commission; write the current plan down in full, including the exceptions nobody documented; and list every rep's opening position (year-to-date attainment, any outstanding draw, any pending clawback). This list is also what you'll reconcile against later.
Big-bang or parallel run: which migration approach is safer?
There are two ways to cut over, and for anything pay-critical the answer is almost always parallel.
| Big-bang cut-over | Parallel run | |
|---|---|---|
| What it is | New tool becomes the source of truth immediately | Old and new run side by side for 1–2 periods, then cut over |
| Speed | Fastest | One or two periods slower |
| Risk to pay | High — errors hit real statements with no safety net | Low — discrepancies caught against the spreadsheet before anyone is paid |
| Best for | Tiny teams, very simple flat plans | Any plan with tiers, splits, accelerators or clawbacks |
| Rollback | Painful — you've already paid | Trivial — the spreadsheet is still live |
The parallel run is the whole game. You calculate a real period in both systems, then reconcile every rep to the penny. Where they disagree, one of them is wrong — and finding out which, before payday, is exactly the protection the migration is supposed to buy you. Our guide to commission reconciliation for finance teams covers how to run that comparison cleanly.
When should you migrate? (Timing matters more than people think)
Never migrate mid-quarter or mid-plan-period. The cleanest cutover is at the start of a new commission period, ideally a new quarter, and well clear of year-end reconciliation. That gives you a clean opening balance and avoids splitting a single period's payout across two systems — which is precisely the kind of seam where money goes missing.
If you're also changing the plan, don't do it in the same cutover. Migrate the existing plan first, prove it reconciles, then change the plan as a separate, communicated event using a proper plan rollout process. Two big changes at once means that when a number looks wrong, you won't know which change caused it.
How do you keep rep trust through the switch?
The fastest way to undo the benefit of new software is to surprise reps with a statement that looks different and unexplained. Reps keep shadow spreadsheets because they've been burned before; a botched migration confirms their worst fear.
Tell them before the first new statement lands: what's changing, why, what stays the same, and where to ask questions. Then use the migration as the moment to give them something the spreadsheet never could — deal-level visibility into how their number is built. When a rep can drill from their total into the individual deals behind it, the shadow spreadsheet loses its reason to exist. If you want the deeper argument for why that visibility matters, see why reps track their own commission.
Frequently Asked Questions
How long does a commission software migration take?
For a small UK team on a reasonably simple plan, a careful migration including one parallel period typically takes four to eight weeks of elapsed time, most of which is data cleaning and the parallel run rather than software setup. Complex plans, messy CRM data or multiple historical schemes push it towards three months. The software configuration is rarely the bottleneck — your input quality is.
How much commission history should we migrate?
Enough to make opening balances and in-flight items correct: current-year attainment for quota-based plans, any outstanding draw balances, and any clawbacks that could still trigger. You rarely need to reload several years of closed, fully-paid history — archive that read-only in the old spreadsheet and migrate the live positions.
Should we run the spreadsheet and the software at the same time?
Yes, for at least one full commission period. A parallel run is the only reliable way to catch configuration errors before they hit real pay. Reconcile every payee against the spreadsheet; only cut the spreadsheet loose once the two agree to the penny.
What's the most common migration mistake?
Migrating dirty CRM data and an undocumented plan, then big-banging the cutover mid-quarter. The tool faithfully reproduces whatever you feed it, so errors that were invisible in the spreadsheet become confident, fast and wrong in the software — landing straight on rep statements with no safety net.
Does migrating change how commission is taxed?
No. Commission remains earnings subject to PAYE and Class 1 National Insurance in the period it's paid, regardless of which system calculates it — see HMRC's employer guide to PAYE and NICs. Migration changes the calculation and audit trail, not the tax treatment; your payroll still runs PAYE.
The bottom line
A commission software migration is a pay change wearing a data-project costume. Treat it like a pay change: clean the inputs, rebuild the plan as-is, run in parallel, reconcile to the penny, and tell reps before their statement changes — not after. The teams that rush straight to cutover are the ones still apologising for a wrong payslip three months later.
Commit is built to make this safe — the parallel-run reconciliation and deal-level rep visibility are the point, not an add-on. If you're weighing the move, our true-cost comparison of spreadsheets vs software and pricing are the honest places to start.
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