Case Studies

Multi-Entity VAT Returns for [UK SaaS Group]

Four BC tenants under one HMRC VRN. Quarterly VAT returns went from a 3-day spreadsheet drill to a 4-hour reviewed-and-signed workflow. Tech: BC + AL extension (UK Group VAT MTD Bridge) + Power Automate + Power Apps.

Amplio Solutions · · 3 min read
Multi-Entity VAT Returns for [UK SaaS Group]

Anonymised at the client's request. Industry, scale, and outcome figures are real; the client name is replaced with a placeholder.

Company snapshot

[UK SaaS Group, ~60 staff, £8–12m ARR, four trading entities under one HMRC VAT registration number.] Group HQ in the South East; subsidiary trading entities in England, Scotland, and Ireland (UK VAT-registered through the Northern Ireland protocol). Finance team of three reporting into a part-time FD.

The challenge

The group had four Business Central tenants — one per trading entity — sitting under a single HMRC VAT registration. BC's standard VAT engine assumes one company per VRN. Each quarter the finance team would export VAT100 figures from each BC company, paste them into a master Excel sheet, hand-reconcile inter-entity transactions, and re-key the consolidated boxes into HMRC's MTD-compliant filing tool.

Three problems with that workflow:

  • Time. Three to four days of senior finance time per quarter, all of it copy-paste-reconcile work that nobody enjoyed.
  • Error rate. One quarter in four shipped with a small reconciliation error caught on internal review; one quarter shipped with an error that had to be voluntarily corrected on the next return.
  • Audit trail. The Excel master was the system of record for "what we filed". If HMRC asked for evidence supporting a specific box, retrieval was a half-day archaeology dig through dated workbooks.

The approach

The group was a beta customer for Amplio's UK Group VAT MTD Bridge extension. The brief was to replace the spreadsheet-and-rekey workflow with a single canonical place where group VAT was assembled, reviewed, signed off, and filed — with per-entity contributions traceable from the consolidated return back to the source BC entries.

Three components:

  1. UK Group VAT MTD Bridge AL extension, installed across all four BC tenants. The extension exposes per-tenant VAT entry data through a secure inter-tenant API and aggregates it into a single group return on the "parent" tenant.
  2. A Power Automate orchestration that runs on the 1st of each VAT quarter: triggers a draft return assembly, runs HMRC's pre-validation, and posts a Teams notification to the finance team with a one-click link to review.
  3. A Power Apps approval canvas for the FD — per-box drill-down to source entries in any of the four BC entities, sign-off button that pushes the return to HMRC's API, and a "reasons changed since last quarter" commentary field that becomes part of the audit pack.

Customer note

“Group VAT used to take three days of senior finance time every quarter, and we'd usually ship a small reconciliation error every other return. With Amplio's bridge we're filing in about four hours, and we have not shipped an error in six quarters. The audit pack went from half a day to five minutes.”

— Group FD, UK SaaS group (multi-entity, single VRN)

The outcome

  • Time per quarter: ~3 days → ~4 hours. Most of that 4 hours is now review, not assembly.
  • Reconciliation errors: zero in the six quarters since go-live (vs. one in roughly every two quarters under the old workflow).
  • Audit pack assembly: ~half a day → ~5 minutes. HMRC asked for box 6 evidence in February 2026 and the FD provided a per-entity breakdown with source-entry links the same morning.

Tech stack

  • Microsoft Dynamics 365 Business Central (Cloud SaaS, four tenants)
  • Custom AL extension — UK Group VAT MTD Bridge (publishing to AppSource Q3 2026)
  • Power Automate — quarter-start orchestration + HMRC submission flow
  • Power Apps canvas — FD review and sign-off interface
  • Microsoft Teams — finance-team notification channel

Engagement shape

Discovery and design: 2 weeks. Build and tenant rollout: 4 weeks. Three full dry-run filings against HMRC's sandbox before the live first return. Total elapsed: 7 weeks.

Post-launch: 90 days of bundled support; the group has since moved to a light retainer covering quarterly readiness checks and BC version-compatibility releases.

Working on a similar problem? Talk to Amplio — the Group VAT pattern generalises to any multi-entity group operating under a consolidated VRN.