Controllers, AP and tax teams
Get back the sales tax, VAT and GST your vendors should not have charged
Reads your AP invoice lines and flags tax charged despite an exemption certificate on file, tax on exempt freight or SaaS, rates above what you expected, tax on tax, purchases you already self-assessed, and VAT or GST on zero-rated exports. It drafts a credit-memo request to each vendor citing the certificate or rule, and never files anything with a tax authority.
The problem
Vendors charge sales tax on purchases that should be exempt, apply the wrong local rate, charge tax on tax, or bill the same tax line twice. The money can be recovered from the vendor, but only if someone matches every taxed line against your exemption certificates and the rate where the goods were delivered.
How it works
- Step 1Export taxed purchase linesFrom your AP ledger with tax detail: vendor, invoice, ship-to, taxable amount and tax charged.
- Step 2Add your certificatesThe exemption or resale certificates you have given each vendor.
- Step 3Run the checksTax charged despite a certificate on file, exempt categories, rates above the expected rate, tax on tax, duplicate tax lines, tax already accrued as use tax, and VAT or GST on supplies outside your country.
- Step 4Set the look-backChoose how far back to go for each state; lines near the edge of that period are flagged.
- Step 5Ask the vendorERPSav drafts a refund or credit-note request to each vendor, who corrects its own return.
Typical results
- Tax charged in error
- 1–3% of the sales tax vendors charged you
- estimate
What the engine checks
- Tax charged despite a resale, manufacturing, nonprofit or government certificate
- Tax on separately stated freight and SaaS where the state does not tax it
- Rates above the expected rate, tax on tax and repeated taxed lines
- Vendor tax on purchases already self-assessed as use tax
- VAT/GST at the standard rate on exports and intra-EU B2B supplies
What you upload
A CSV export. Header names are matched automatically; these are the columns the engine reads.
| Column | Required | Example |
|---|---|---|
| Vendor | Yes | Midwest Industrial Supply |
| Invoice number | Yes | INV-55120 |
| Invoice date | 2026-03-04 | |
| Line | 1 | |
| Description | Hydraulic press parts | |
| Item category | Manufacturing equipment | |
| Ship-to state / province | TX | |
| Ship-to country | US | |
| Vendor state | IL | |
| Vendor country | US | |
| Taxable amount | Yes | 8400.00 |
| Tax charged | Yes | 693.00 |
| Tax rate charged | 8.25 | |
| Expected rate | 8.25 | |
| Exemption certificate on file | Y | |
| Exemption type | Manufacturing | |
| Certificate number | TX-MFG-2231 | |
| Certificate state | TX | |
| Certificate expiry | 2028-12-31 | |
| Use tax self-assessed | N | |
| Export / zero-rated evidence | ||
| Buyer VAT number | DE123456789 |
What you need
- Purchase lines with tax amounts from your AP system: vendor, invoice, ship-to, taxable amount and tax charged
- The exemption or resale certificates you have given vendors
- Ship-to addresses or locations, to check the local rate
Worked examples
Questions
- How far back can we go?
- Each state sets its own refund time limit; Texas, for example, allows four years. You set the look-back per state and ERPSav flags lines about to fall outside it. Confirm the limit for your state with your tax adviser.
- Do you file with the tax authority?
- No. ERPSav drafts a request to the vendor, who refunds you and corrects its own return. A filing with a state needs that state's power of attorney and goes through you or your tax adviser.
- Is it available in every country?
- It is offered in the US, Canada and the UK. In the UK the request is for a supplier credit note, and ERPSav never contacts HMRC. It is not offered in Australia.
- Is this tax advice?
- No. ERPSav checks invoices against the certificates and rates you provide and shows the arithmetic. Whether a purchase is exempt is for you and your tax adviser to confirm.
- What does it cost?
- Self-serve plans start at $299 a month and you keep 100%. The Recovery plan is $99 a month for this module plus 15% of money credited to you. Managed is 30% of what is recovered.
- Is our data safe?
- Your files go into your own workspace, and every row is scoped to it, so no other customer can see them. Imports, letters and status changes are written to an audit trail with who did what and when. ERPSav runs on its own servers in the EU behind Cloudflare, and most modules work from a CSV export, so nothing is installed.
ERPSav drafts requests to vendors only, never files with a tax authority and gives no tax advice; it is not offered in Australia.