CIS

Is a CIS nil return due?

Says whether a contractor must file a CIS nil return for a tax month (SI 2005/2045 reg 4(9A) and (9B), inserted by SI 2026/289 from 6 April 2026): due when a mainstream contractor that has paid subcontractors before pays none that month, unless it told HMRC no later than 14 days before the month started. Takes the tax year and month and yes or no answers. Returns whether a nil return is due, why, and the date it is due. Does not file anything. The same as the GET, with the input as a JSON body.

post/api/v1/nil-return-check

Request

  • Base URL: https://0sand1s.co.uk
  • URL: https://0sand1s.co.uk/api/v1/nil-return-check
  • Auth: none declared

Request body

tax_yearinteger required

The tax year, by the calendar year it starts in: 2026 for 6 April 2026 to 5 April 2027

tax_monthinteger required

The tax month, 1 to 12: 1 is 6 April to 5 May, 12 is 6 March to 5 April

paid_subcontractors_in_monthboolean required

true if any subcontractor was paid in that tax month, gross payments included

paid_subcontractors_beforeboolean required

true if the contractor had paid any subcontractor before that tax month started

mainstream_contractorboolean

true for a mainstream contractor (a construction business). false for a deemed contractor, which is outside the nil return rule

told_hmrc_no_payments_onstring

If the contractor told HMRC in advance that no payments would be made in that month, the date it did so. Leave out if not, YYYY-MM-DD

Response

The answer

toolstring required
resultobject required

The answer. Amounts are { pence, pounds } objects; dates are YYYY-MM-DD.

summarystring required

The answer in one line

see_alsostring uri required

The page on 0sand1s.co.uk that does the same sum or explains the rule

Changes

No recorded changes to this operation across all 1 revision of this API.