Periods

A financial year in Twinfield is divided into periods, usually the 12 months, plus special periods for the opening balance and the year end. Every transaction is booked in a period, e.g. 2026/11. The periods service (PeriodService) reads the years and periods of a company, and opens, closes, renames and creates them.

Twinfield documentation	Resource	Status
Periods GetYears, GetPeriods	$twinfield->periods()->years(), list(), get(), find()	Verified live (read-only)
Periods ChangeName	changeName()	Tested offline; composer test:write changes a name live and restores it
Periods ChangeEndDate, OpenPeriod, ClosePeriod, CreateYear, DeleteYear, ResetYears	changeEndDate(), open(), close(), createYear(), deleteYear(), resetYears()	Only tested offline

The PeriodService is a Command & Query web service. It always works on one company, given in the request header: $twinfield->company('1000')->periods(). Without a company, the SDK throws a LogicException before sending.

At a glance

use SolveBeam\Twinfield\Period\Period;

$periods = $twinfield->company('1000')->periods();

$periods->years();                                  // [2024, 2025, 2026]

foreach ($periods->list(2026) as $details) {
    echo $details->period, ' ', $details->name ?? '-', ' ', $details->open ? 'open' : 'closed', PHP_EOL;
}

$transaction = $twinfield->journalTransactions()->get('MEMO', 202600012);

$periods->get($transaction->header->period)->open;  // can the transaction still be changed?

$periods->close(Period::of(2026, 1));

2026/00 Openingsbalans 2026 open
2026/01 januari 2026 open
…
2026/12 december 2026 open
2026/55 Voorafgaande journaalposten 2026 open

Period and PeriodDetails

The SDK has two classes for a period:

• Period is the year and the period number, e.g. 2026/11. It is the value Twinfield uses in transactions (<period>), browse data (fin.trs.head.yearperiod), budgets, general ledger accounts (activeFrom, activeUntil) and fixed assets. Create one with Period::of(2026, 11) or Period::fromString('2026/11'); it prints as 2026/11. Compare two periods with equals().
• PeriodDetails is what the PeriodService returns for a period: period (a Period), name, endDate, open and company.

So the period of a transaction is a Period, and periods()->get($period) gives its PeriodDetails:

$period = $transaction->header->period;             // Period 2026/03
$details = $twinfield->periods()->get($period);     // PeriodDetails

$details->name;                                     // 'maart 2026'
$details->endDate;                                  // DateTimeImmutable 2026-03-31
$details->open;                                     // true

get() reads all periods of the year. For many transactions, call list($year) once per year and look up the periods yourself: see Period of transaction.

Years and special periods

years() returns the years of the company as integers. list($year) returns all periods of a year, sorted by number. Besides the regular periods (1–12 for a year with 12 periods), a year has special periods:

Period	Name in Twinfield (Dutch)	Used for
0	Openingsbalans	The opening balance, e.g. day book BEGINBALANS
55	Voorafgaande journaalposten	Year end bookings, e.g. day book VJP

Special periods have no end date: endDate is null. The end date of a regular period is its last day; a financial year does not have to follow the calendar year.

Period names are in the language of the company. Twinfield returns an empty name (<Name/>) for all periods of some years, often older ones: name is null then.

Open and closed periods

A closed period cannot be booked in. open tells whether a period is open; open($period) and close($period) change it.

$periods->close(Period::of(2026, 1));
$periods->open(Period::of(2026, 1));

Saving a transaction in a closed period is refused with a ProcessXmlException. The exact message is not verified yet.

Changing periods and years

Method	Command	What it does
changeName($period, $name)	ChangeName	Changes the name of a period
changeEndDate($period, $endDate)	ChangeEndDate	Changes the end date of a period
open($period), close($period)	OpenPeriod, ClosePeriod	Opens or closes a period
createYear($numberOfPeriods)	CreateYear	Creates a new year, e.g. with 12 periods
deleteYear($year)	DeleteYear	Deletes a year
resetYears($newYear, $newNumberOfPeriods)	ResetYears	Deletes all years and starts again from $newYear

Commands return nothing. Only run deleteYear() and resetYears() on a test company. See Rename period.

Errors

When Twinfield refuses a query or command, the SDK throws a CommandQueryFaultException with type PeriodServiceFault and an errorCode from PeriodServiceFaultCode:

use SolveBeam\Twinfield\Period\PeriodServiceFaultCode;
use SolveBeam\Twinfield\Soap\CommandQueryFaultException;

try {
    $periods->close(Period::of(2026, 1));
} catch (CommandQueryFaultException $exception) {
    if (PeriodServiceFaultCode::tryFrom($exception->errorCode) === PeriodServiceFaultCode::PeriodCanNotBeClosed) {
        echo $exception->errorMessage, PHP_EOL;
    }
}

The codes are YearNotFound, PeriodNotFound, YearCanNotBeDeleted, InvalidNumberOfPeriods, YearCanNotBeCreated, EndDateCanNotBeChanged, NameCanNotBeChanged, PeriodCanNotBeOpened and PeriodCanNotBeClosed. The message is in the language of the user, e.g. Year 1901 bestaat niet.

get() throws a PeriodNotFoundException instead when the year does not exist (YearNotFound) or has no period with that number; find() returns null then.

Organisation and company

Periods belong to a company. PeriodDetails::$company is a CompanyReference with the organisation and the company code, so periods of different organisations can be kept apart. See Organisations and companies.

Differences with the documentation

See Periods in the differences with the documentation.