METHOD & GUIDANCE
How this calculation works
Enter figures from the same period and on a consistent VAT-inclusive or VAT-exclusive basis. Tool IQ recalculates every output immediately; nothing you enter is saved or sent to us.
How to use the result
Update the inputs from current VAT records, ring-fence the resulting liability from operating cash and revise the plan whenever sales, purchases or adjustments change.
Worked example
The opening example has 12,000 output VAT, 3,500 reclaimable input VAT and a 500 net adjustment. That estimates a 9,000 liability; after a 5,000 reserve, another 4,000 is required.
Common mistakes
- Using gross sales or purchase values instead of the VAT amounts.
- Assuming every purchase VAT amount is reclaimable.
- Treating the reserve estimate as the submitted VAT return or final amount due.
Frequently asked questions
Is the vat reserve planner free?
Yes. It requires no account and stores no calculation inputs.
Can I use the answer for a formal filing?
No. It is a planning estimate, not accounting, tax, legal or investment advice. Confirm material decisions with a qualified professional.
Does this calculator choose the correct VAT rate for me?
No. Enter the rate that applies to the supply. UK goods and services can be standard-rated, reduced-rated, zero-rated, exempt or outside the scope.
Continue the decision
- VAT Calculator — Add or remove VAT with a transparent breakdown.
- Cash Flow Forecast Calculator — Project closing cash from collections, payments and one-off movements.
- VAT Registration Threshold Calculator — Track taxable turnover against the UK VAT registration threshold.
Method reviewed 26 July 2026. Figures are illustrative and calculated locally in your browser.