New South Wales residents are being urged to check if they are owed some of the $300m sitting in Revenue NSW’s unclaimed money pool.

The pool includes funds from overpayments, uncashed cheques, dividends, refunds, and other amounts owed to individuals the government has not been able to contact.

The funds go unclaimed in instances including when people forget to update their names or contact details with a business, lose important paperwork or when estates are unaware of funds belonging to deceased relatives.

Sydney’s city and eastern suburbs have the highest amount of unclaimed money with more than $91m waiting to be claimed.

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The next largest area is western Sydney with about $77m, while in the regions, residents of the Central Coast and Hunter have $22m unclaimed.

Residents outside NSW who have conducted business in the state may also be eligible, with almost $395m in additional money for people registered at interstate addresses.

“We want to make sure as much of that as possible finds its way back to families,” the government procurement minister, Courtney Houssos, said.

“Last financial year, Revenue NSW returned more than $21m to its rightful owners. With these new reforms, we’re making it faster and easier for people to get what they’re owed.”

Houssos flagged legislative changes aimed at streamlining the system, including reducing the time businesses can only hold on to the money from six years to two in order “to make it again easier for people to get access to their money”.

Those wondering if they are a recipient can search their name on the Revenue NSW unclaimed money portal and lodge a claim.

Claims must include two proof of identity documents such as an Australian driver’s licence, proof of age card, Australian birth certificate or a Medicare card.

Revenue NSW also requires one official document as proof of a connection to the money, including an electricity or phone bill, bank statement or a residential lease agreement.

Revenue NSW says claims can take up to 28 days to verify that a person is legally entitled to the money.