Software
Subscription tools we build and run ourselves.
Reinza Reminder
Tracks statutory filing deadlines for the limited companies you act for, and emails you before they fall due. Syncs daily with Companies House.
£4.99 a month, or £20 a year
Visit Reinza Reminder →Reinza Sign
Send engagement letters and client approvals for signature, and keep the signed copies together.
Reinza Timesheet
Record time against clients and jobs, for practices that bill by the hour.
Reinza MTD
Keep digital records and file quarterly updates under Making Tax Digital for Income Tax.
Free Calculators & Tools
Free to use, no sign-up required.
People & Payroll
Probation Tracker
Track probation end dates, review meetings and notice deadlines for new employees.
Auto-enrolment Checker
Check a worker's automatic-enrolment category and the general employer action under the 2026/27 Great Britain rules.
Use this free tool →New Starter Form
Collect the details you need from a new employee in one place.
Use this free tool →SSP Calculator
Work out Statutory Sick Pay under the 2026 rules — 80% of average weekly earnings or the flat rate, whichever is lower.
Minimum Wage Checker
Check whether pay meets the National Minimum Wage once deductions, working time and age bands are taken into account.
Employer NIC Calculator
Work out employer National Insurance on a salary, including whether the Employment Allowance is available.
Holiday Calculator
Calculate holiday entitlement for part-year and irregular hours workers.
Tax & Property
Income Tax Calculator
Income tax, National Insurance and student loan repayments on a salary.
Corporation Tax Calculator
Corporation tax including marginal relief between £50,000 and £250,000.
Salary & Dividend Calculator
Compare take-home pay across different salary and dividend splits under the 2026/27 rates.
UK Statutory Residence Test
Work through the Statutory Residence Test to establish UK tax residence for a tax year.
VAT Threshold Tracker
Track rolling twelve-month turnover against the VAT registration threshold.
Property CGT Calculator
Capital gains tax on a residential property disposal, including reliefs and the annual exempt amount.
Private Residence Relief Calculator
Work out qualifying periods of occupation for Private Residence Relief.
Invoicing & Cash Flow
Invoice
Create and download a VAT invoice, with your own details saved for next time.
Quote
Produce a quotation on the same template, ready to turn into an invoice.
Payment Chaser
Draft a payment reminder pitched at the right level for how overdue the invoice is.
Late Payment Calculator
Statutory interest and compensation on a commercial debt paid late.
Expenses & Records
Mileage Log
Record business mileage and calculate the claim at HMRC's approved rates.
Expense Claim
Build an expense claim from receipts and produce a summary you can file.
Home Office Calculator
Compare the simplified flat rate against actual costs for working from home.
Deadlines & Filings
Filing Calendar
Enter a year end and get every statutory filing date that follows from it.
Penalty Calculator
Work out what a late filing costs at Companies House and at HMRC.
Managing several companies? See Reinza Reminder.
Need something that is not here?
If there is a calculation or a form you find yourself rebuilding every time, tell us. Several of these started as something we built for one client.
Get in Touch →