Self Assessment software that prepares every client's SA100 ready for HMRC by the filing deadline.
Let AI Agent run your Self Assessment
Gather income
"Gather last tax year's income for this client across every source. Pull P60, P45 and P11D from Gmail and the shared folder, collect self-employment records from the ledger, property income, dividend vouchers, savings interest, foreign income and any capital gains records the client has shared. Identify which supplementary pages are needed. If a source is incomplete or the prior year showed an income type not yet evidenced, ask me whether to chase the client or refer to the senior. Pause before chasing. Ask me where the practice stores last year's return. Save a note for the practice manager listing complete sources, missing items and clients ready for SA100 build."
Build SA100 pages
"Build the SA100 main return and the supplementary pages for this client in Xero. Apply the income data gathered, the prior-year balancing positions, the agreed reliefs and any client-specific deductions. Complete SA102 for employment income, SA103 for self-employment, SA105 for UK property and SA108 for capital gains as required. Tie every figure on the return to its source document. If the income mix has changed materially from last year, ask me whether to refer to the senior. Pause before locking the return. Ask me where the practice keeps the client's tax memorandum if I cannot find the file. Save a note for the practice manager listing return drafts complete, exceptions and clients awaiting senior review."
Apply allowances
"Apply this year's tax allowances and reliefs for this client in QuickBooks. Compute the personal allowance taper above the agreed income threshold, apply the marriage allowance transfer where the practice has the election on file, pension contribution relief at the marginal rate, gift aid relief and any blind person's allowance. For self-employed clients, apply trading allowances, capital allowances and loss relief where beneficial. If an allowance election needs the client's confirmation, ask me whether to draft the request or pause. Pause before changing an election from prior year. Save the allowances working paper and the supporting evidence to Google Drive ready for senior sign-off before the return is locked."
File with HMRC
"File this client's Self Assessment with HMRC from FreeAgent through the practice's Agent Services Account. Submit the SA100 with the relevant supplementary pages attached, capture the HMRC receipt reference and confirm the balancing payment due at the filing deadline plus the two payments on account due in the following tax year. If HMRC returns a validation error, read the error, identify the page or field that caused it and prepare the correction for senior review. Pause before resubmitting. Ask me where the practice files the receipt evidence. Save a note for the practice manager listing submission status, receipt reference, balancing payment timing and the payments-on-account schedule for the year ahead."
Self assessment filings without manual chase
SA100 prep, supplementary pages, income reconciliations and HMRC-document chase stop running on staff one client at a time. The AI Agents repeat the SA motion across the personal-tax book, which is where the up to 80% lower cost to serve per return comes from, with manager review held on judgement.
SA100 preparation that learns each client's tax position
Personal tax is mostly continuity. Minded carries each client's allowances elected, payments on account, capital allowances pool, property portfolio, residence position and prior reliefs. The next SA100 starts where the last one ended. Tie this to MTD compliance with AI so quarterly ITSA updates and the annual return share a single picture.
One Self Assessment flow across practice client files
A real practice prepares Self Assessment returns across many personal clients. Some pull from Xero, QuickBooks or FreeAgent self-employment records; others bring their own pack. See CT600 with AI for owner-managed company directors and compliance management with AI for the surrounding compliance position.
How does this differ from MTD for Income Tax?
MTD ITSA is the quarterly digital update and the end-of-period statement. Self Assessment is the SA100 personal tax return and its supplementary pages, covering employment, self-employment, property, capital gains and other income. Minded prepares the full SA100 from the year's records and the supplementary pages required for each income type.
How does the agent handle SA102, SA103, SA105 and SA108 supplementary pages?
The agent identifies which supplementary pages each client needs from the year's records, completes SA102 for employment income from P60 and P11D, SA103 for self-employment from the business records, SA105 for UK property and SA108 for capital gains from disposal records the client has shared.
Can the agent compute payments on account and the balancing payment?
Yes. The agent computes the balancing payment due at the filing deadline and the two payments on account due in the following tax year. Where last year's payments on account were reduced or claims made, the agent reflects that in the schedule and the cash impact.
What about capital gains tax, residence basis and remittance basis claims?
For capital gains the agent compiles the disposal schedule, applies the annual exempt amount and the relevant CGT rate by asset class. For residence and domicile, the agent applies the statutory residence test, drafts the remittance basis claim where applicable and pauses for senior review on any non-domicile position.
How does the agent submit through the Agent Services Account?
Each client's authorisation is held in the practice's Agent Services Account. The agent submits the SA100 and supplementary pages, captures the HMRC receipt reference, schedules any payment due and notifies the responsible team once the return is filed and the receipt is on file.