Self Assessment

#A year's Self Assessment figures

Address

https://<your-org>.brambleit.cloud/simplebooks/api/companies/:companyId/tax-return

Requires

Signed-in browser session (the sso_session / session_id cookies from Bramble sign-in).
Licence: SimpleBooks.

Path parameters

Query parameters

Response 200

{
  "tax_year": null,
  "status": "active",
  "filed_at": "2026-11-12T09:30:00.000Z",
  "hmrc_reference": null,
  "notes": [],
  "use_trading_allowance": false,
  "figures": [],
  "changed_since_filing": null,
  "company": {
    "name": "Example name",
    "utr": null,
    "year_end": null
  },
  "can_edit": true
}

Example request

// From a page served by Bramble (uses the signed-in session)
const res = await fetch('/simplebooks/api/companies/1/tax-return', {
  method: 'GET',
  credentials: 'include',
});
const data = await res.json();

#Save Self Assessment choices

Address

https://<your-org>.brambleit.cloud/simplebooks/api/companies/:companyId/tax-return

Requires

Signed-in browser session (the sso_session / session_id cookies from Bramble sign-in).
Licence: SimpleBooks.

Path parameters

Request body JSON

Response 200

{
  "ok": true
}

Errors

Example request

// From a page served by Bramble (uses the signed-in session)
const res = await fetch('/simplebooks/api/companies/1/tax-return', {
  method: 'PUT',
  credentials: 'include',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify({"tax_year":"…","use_trading_allowance":"…","notes":"string"}),
});
const data = await res.json();

#Mark a year filed

Address

https://<your-org>.brambleit.cloud/simplebooks/api/companies/:companyId/tax-return/file

Requires

Signed-in browser session (the sso_session / session_id cookies from Bramble sign-in).
Licence: SimpleBooks.

Path parameters

Request body JSON

Response 200

{
  "ok": true
}

Errors

Example request

// From a page served by Bramble (uses the signed-in session)
const res = await fetch('/simplebooks/api/companies/1/tax-return/file', {
  method: 'POST',
  credentials: 'include',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify({"tax_year":"…","hmrc_reference":"string"}),
});
const data = await res.json();

#Reopen a filed year

Address

https://<your-org>.brambleit.cloud/simplebooks/api/companies/:companyId/tax-return/reopen

Requires

Signed-in browser session (the sso_session / session_id cookies from Bramble sign-in).
Licence: SimpleBooks.

Path parameters

Request body JSON

Response 200

{
  "ok": true
}

Example request

// From a page served by Bramble (uses the signed-in session)
const res = await fetch('/simplebooks/api/companies/1/tax-return/reopen', {
  method: 'POST',
  credentials: 'include',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify({"tax_year":"…"}),
});
const data = await res.json();

#Self Assessment summary as PDF

Address

https://<your-org>.brambleit.cloud/simplebooks/api/companies/:companyId/tax-return/pdf

Requires

Signed-in browser session (the sso_session / session_id cookies from Bramble sign-in).
Licence: SimpleBooks.

Path parameters

Query parameters

Response

A body.

Example request

// From a page served by Bramble (uses the signed-in session)
const res = await fetch('/simplebooks/api/companies/1/tax-return/pdf', {
  method: 'GET',
  credentials: 'include',
});
const data = await res.json();